I've got a problem…
Question:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about? 
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
We could have used this info three years ago when our Suburban cooked the transmssion. To be fair we had no clue about tcc bore wear but we did experience "hard" 1- 2 shifts and slipping 2-3 shifts.Severe slipage at highway speeds in 4th od with reflecting high coolant temps was our clue something was amiss… The trans rebuilder was sure that the 3rd and 4th clutches and seals were toast and recomended a rebuild. With the unit on the bench torn down for inspection ,I noted that the afore mentioned clutches were not worn or glazed. I also noted the the condition of pressure regulating solenoid filter (clogged) after asking the tech some questions about the valve body.He proceded to move the valves where I noted one appeared stuck in the bore.I don’t remember which one though.The valve body was not changed to my knowledge. The trans fluid was burnt (a sign of heat) though the tech could not isolate the source…couldn’t see inside the converter… After many internals (steels for one) were replaced and solenoids and the toque converter and a shift improver kit too we have been running trouble free since. I do feel taken however because my questions re heat and valves and clutch condition were not answered. Does a shift improver kit really work in an adaptive unit? I can’t tell as I have not driven any other trucks with known good oem transmissions installed. Am I on the right track….does the powertrain control module "remember" operating conditions and then make adjustments accordingly? Rolf
Response:
No problem. Here’s a link to a technical artical that discusses the subject. http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf
– Hide quoted text — Show quoted text -> hey, I said ‘if you cannot monitor TC slip with a scan tool’ > obviously, you can and did > but I get at least two customers a month in here, who > couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff > themselves, and are now PISSED that it STILL ‘doesn’t work’. > Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the > tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in > the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > > Gary, can you explain your comments so we can all learn from your > > expertise? > > > What part of knuckles advice do you disagree with? I have a > competent > > > tranny guy I go to but I like to sound at least halfway intelligent > when > I > > > talk to him. Thanks. > > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > > cannot monitor ‘TCC slip’ with a scan tool afterwards. > > All the Sonnax parts in the world will NOT fix a converter that has > slipped > > until the lock-up clutch material has glazed or burnt to a crisp. > > And, usually, by the time it is noticeable (code) it is past the point > of > a > > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > > body’ repair spiel.
Response:
hey, I said ‘if you cannot monitor TC slip with a scan tool’ obviously, you can and did but I get at least two customers a month in here, who couldn’t/wouldn’t/didn’t, but who went ahead and installed the Sonnax stuff themselves, and are now PISSED that it STILL ‘doesn’t work’.
– Hide quoted text — Show quoted text -> Gary, not meaning to dispute your vast knowledge of transmissions, but my > advice comes from direct experience. > TCC slip can be measured using a Tech 2. We ran one of my trucks with the > Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget > the spec, but if the tranny slips at around 130 rpm for more than some > number of seconds (I think around 7), the P1870 code gets set and the tranny > starts shifting hard. The problem is intermittant at first. My converter > was no doubt broaching those thresholds from time to time, resulting in the > hard shifts I was getting. Thurman’s most likely is too. All I know is if > you take care of it before the converter wears too much, you can avoid > having replace or rebuild the unit. > Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat > modified tranny that comes with a carbon fibre torque converter. The > valving is a little different to permit greater slippage of the torque > converter during lock-up so I’d guess his converter can take more abuse > longer than my ‘97 could.. Even so, they still have the TCC bore wear > problem. > If Thurman can find someone with a Tech 2 to measure his converter slip, > then he can do the same as I did. All I know is, it took me a year to > figure out that this was the problem. Finally, a friend of mine who works > in product development at GM Hydramatic turned me on to the fix. > I took his advice, and it worked. > > Gary, can you explain your comments so we can all learn from your > expertise? > > What part of knuckles advice do you disagree with? I have a competent > > tranny guy I go to but I like to sound at least halfway intelligent when > I > > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if > you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has > slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of > a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar > valve > body’ repair spiel.
Response:
Gary, not meaning to dispute your vast knowledge of transmissions, but my advice comes from direct experience. TCC slip can be measured using a Tech 2. We ran one of my trucks with the Tech 2 plugged in. It was showing about 120 rpm converter slip. I forget the spec, but if the tranny slips at around 130 rpm for more than some number of seconds (I think around 7), the P1870 code gets set and the tranny starts shifting hard. The problem is intermittant at first. My converter was no doubt broaching those thresholds from time to time, resulting in the hard shifts I was getting. Thurman’s most likely is too. All I know is if you take care of it before the converter wears too much, you can avoid having replace or rebuild the unit. Not to further confuse the issue, but Thurman’s ‘98 likely has a somewhat modified tranny that comes with a carbon fibre torque converter. The valving is a little different to permit greater slippage of the torque converter during lock-up so I’d guess his converter can take more abuse longer than my ‘97 could.. Even so, they still have the TCC bore wear problem. If Thurman can find someone with a Tech 2 to measure his converter slip, then he can do the same as I did. All I know is, it took me a year to figure out that this was the problem. Finally, a friend of mine who works in product development at GM Hydramatic turned me on to the fix. I took his advice, and it worked.
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
OK. Should one, in your opinion, upgrade a tranny that’s still working right to avoid the problem or wait and plan on a complete rebuild when necessary (rather than "throwing parts at it")?
– Hide quoted text — Show quoted text -> Gary, can you explain your comments so we can all learn from your > expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks. > I disagree with throwing parts (the Sonnax valve, in this case) at it if you > cannot monitor ‘TCC slip’ with a scan tool afterwards. > All the Sonnax parts in the world will NOT fix a converter that has slipped > until the lock-up clutch material has glazed or burnt to a crisp. > And, usually, by the time it is noticeable (code) it is past the point of a > ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve > body’ repair spiel.
Response:
It was worth a shot, the end came off the trans on my hot rod, made the same problem. Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
Maybe your truck has a shift commander (shift improver) on it that is set to the tow setting. — — 98 Camaro Money can’t buy happiness, but it sure makes misery easier to live with.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
> Gary, can you explain your comments so we can all learn from your expertise? > What part of knuckles advice do you disagree with? I have a competent > tranny guy I go to but I like to sound at least halfway intelligent when I > talk to him. Thanks.
I disagree with throwing parts (the Sonnax valve, in this case) at it if you cannot monitor ‘TCC slip’ with a scan tool afterwards. All the Sonnax parts in the world will NOT fix a converter that has slipped until the lock-up clutch material has glazed or burnt to a crisp. And, usually, by the time it is noticeable (code) it is past the point of a ’simple fix’, contrary to GM’s official ‘let us sell you a 700 dollar valve body’ repair spiel.
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Gary, can you explain your comments so we can all learn from your expertise? What part of knuckles advice do you disagree with? I have a competent tranny guy I go to but I like to sound at least halfway intelligent when I talk to him. Thanks.
Response:
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
I spoke with a guy at the dealer, and he said that late model autos have the ability to readjust themselves to new driving styles, and that the problem was probably related to that. He said that it would probably go away in a couple of days. Does that sound realistic, or am I being jived?
Response:
They do talk like computer people, don’t they. Got their own language and everything! Seriously, your best shot is to find a local independent AT rebuilder who knows his stuff. Ask around. Visit the shop. Ask questions. If he doesn’t savvy the valve body deal, go elsewhere. Ask about warranties. Sometimes you can ask around at 4×4 shops and travel trailer shops for a good tranny mechanic. The owner of your local NAPA might be able to steer you to a good shop. You can always go the national rebuilder route too, like www.jetchip.com or www.tciauto.com. Pricey but good. Hint: If you ever buy another GM truck, get one with the 4L80E. It’s the old TH400 on steroids. I’ve tried, believe me, I’ve really tried, but you just can’t break them. Dean – Hide quoted text — Show quoted text ->>There is a third option if you want to do it right, and save some dough: >>Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is >>harder than the current bore. The kit costs around $65. You’ll need a >>special reamer they sell for $75 to open up the TCC bore. Once that’s >done, >>simply insert the sleeve, put in the new spring and valve, and reinstall >the >>valve body. By the way, when you have the valve body out, you may as >well >>replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes >the >>hard shift can come from failure of this part but most often it’s the >TCC >>valve. The TCC "Apply" valve is located in the pump itself, and is >>accessable with the valve body out. Just pull the old one out, and >insert >>the new replacement. The new one fits the bore better and has a teflon >seal >>that the OEM part doesn’t have. It’s about $35. For more informaion, >visit >>Sonnax’s web site at www.sonnax.com. >yes, by all means, go ahead and do that without being able to check TCC >slip >when you are finished. >Does anybody know of a good Transmission-to-English dictionary I could use >to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s > done, > simply insert the sleeve, put in the new spring and valve, and reinstall > the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes > the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon > seal > that the OEM part doesn’t have. It’s about $35. For more informaion, > visit > Sonnax’s web site at www.sonnax.com. > yes, by all means, go ahead and do that without being able to check TCC slip > when you are finished.
Does anybody know of a good Transmission-to-English dictionary I could use to figure out what these guys are talking about?
Response:
– Hide quoted text — Show quoted text -> There is a third option if you want to do it right, and save some dough: > Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is > harder than the current bore. The kit costs around $65. You’ll need a > special reamer they sell for $75 to open up the TCC bore. Once that’s done, > simply insert the sleeve, put in the new spring and valve, and reinstall the > valve body. By the way, when you have the valve body out, you may as well > replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the > hard shift can come from failure of this part but most often it’s the TCC > valve. The TCC "Apply" valve is located in the pump itself, and is > accessable with the valve body out. Just pull the old one out, and insert > the new replacement. The new one fits the bore better and has a teflon seal > that the OEM part doesn’t have. It’s about $35. For more informaion, visit > Sonnax’s web site at www.sonnax.com.
yes, by all means, go ahead and do that without being able to check TCC slip when you are finished.
Response:
Ah, so *that’s* why I couldn’t find it.
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
Response:
A lot of us have had the same problem. You have a 4L60E transmission. It’s electronically controlled which means the shifts are solenoid actuated. They switched to an aluminum valve body. Previously the valve bodies had been cast iron. GM has, or had a problem with the TCC valve wearing the bore in the valve body. That’s what’s happening to you. If you go to your dealer and have him read the codes off your ECM they’ll no doubt tell you they’re getting a P1870 code. It’s a general code that means the ECM sensed an internal slippage. The hard shift is the result of the ECM commanding maximum line pressure in order to accomplish the shifts without burning up clutches. What’s happening internally is that the TCC, or Torque Converter Clutch valve has worn the bore and fluid is getting past it. This reduces pressure in the circuit that actuates the torque converter lock-up. If you don’t fix this, sooner or later you’ll be replacing your torque converter. Dealers who know what they’re doing will recommend a new valve body. It will come with a longer TCC valve -presumably this one will rock less in the bore and cause less wear. Clueless dealors will simply tell you to replace the transmission with a new Serta unit. The first option costes $400-500; the second upwards of $2,000. There is a third option if you want to do it right, and save some dough: Sonnax makes a TCC valve kit that includes a new sleeve. The sleeve is harder than the current bore. The kit costs around $65. You’ll need a special reamer they sell for $75 to open up the TCC bore. Once that’s done, simply insert the sleeve, put in the new spring and valve, and reinstall the valve body. By the way, when you have the valve body out, you may as well replace the TCC apply valve with Sonnax’s aftermarket valve. Sometimes the hard shift can come from failure of this part but most often it’s the TCC valve. The TCC "Apply" valve is located in the pump itself, and is accessable with the valve body out. Just pull the old one out, and insert the new replacement. The new one fits the bore better and has a teflon seal that the OEM part doesn’t have. It’s about $35. For more informaion, visit Sonnax’s web site at www.sonnax.com.
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Look on the vacuum modulator on the trans or the rubber fittings either there or where it plums into the intake. A vacuum leak will cause your trans to shift at a higher rpm, and it will be harsher. Grease
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Grease, Vacuum modulators died with the invention of electronic transmissions. Dean – Hide quoted text — Show quoted text – >Look on the vacuum modulator on the trans or the rubber fittings either >there or where it plums into the intake. A vacuum leak will cause your trans >to shift at a higher rpm, and it will be harsher. >Grease >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that >I >was feeling the clunk when the torque drops it (that had happened to me >with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
There have been ppl saying the same thing abt harsh 1-2 shifts on the full-size trucks … I think a computer update fixes it … don’t know if it would be the same on yours or not but just a thought
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
Axle wrap? Are there blocks on the rear axle? If so…solution could be traction bars or replace stock springs and blocks for lift springs. HH
– Hide quoted text — Show quoted text -> 1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. > Great vehicle, but sometimes (often) when I’m accelerating from a stop, I > get a "kick in the pants" when I hit second gear. The vehicle noticeably > jumps forward. > My first reaction was to think it was a loose motor (bad mounts) and that I > was feeling the clunk when the torque drops it (that had happened to me with > a previous vehicle). But then I figured that bad mounts wouldn’t make the > vehicle jump forward like it does. > Maybe I just need to get the transmission flushed? > Any suggestions or recommendations?
Response:
It would depend on how fast you are accelerating, you maybe making the transmission "kick down" to a lower gear. If it’s not that, change the transmission fuild and filter, and put in a good synthetic fluid like Mobil 1 (they make an auto transmission fluid). If you dont have any luck, take it to a mechanic and have them check it out. – Hide quoted text — Show quoted text – >1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. >Great vehicle, but sometimes (often) when I’m accelerating from a stop, I >get a "kick in the pants" when I hit second gear. The vehicle noticeably >jumps forward. >My first reaction was to think it was a loose motor (bad mounts) and that I >was feeling the clunk when the torque drops it (that had happened to me with >a previous vehicle). But then I figured that bad mounts wouldn’t make the >vehicle jump forward like it does. >Maybe I just need to get the transmission flushed? >Any suggestions or recommendations?
Response:
1998 Chevy Blazer 4×4 4-door. Just bought it a few days ago. Great vehicle, but sometimes (often) when I’m accelerating from a stop, I get a "kick in the pants" when I hit second gear. The vehicle noticeably jumps forward. My first reaction was to think it was a loose motor (bad mounts) and that I was feeling the clunk when the torque drops it (that had happened to me with a previous vehicle). But then I figured that bad mounts wouldn’t make the vehicle jump forward like it does. Maybe I just need to get the transmission flushed? Any suggestions or recommendations?
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