1996 Tahoe Transmission Problems?

[laynel]

Have a 1996 Tahoe 2wd 4dr 5.7l Vortec, 64k mi. (bought 4 yrs ago, put 18k mi on it). Had 60k mi service May 2003, incl. flush/fill tranny. Tranny started slipping in Jan 2004 at hwy speeds; discovered fluid ONE QUART LOW! Put in fluid, everything fine, took back to mech who did 60k service for checkover, no problems, no leaks (have checked since, no leaks). April 2004, w/ac on, at hwy speeds, tranny slipped (revved slightly on tach, no increase in speed). Mech can't reproduce, can'd find anything wrong, NO CODE in computer! I've seen a number of posts about Tahoe tranny problems. Any suggestions? (Sell or invest in $2500 to rebuild tranny?) Thanks for help!

[GMMerlin]

Originally Posted by laynel

Have a 1996 Tahoe 2wd 4dr 5.7l Vortec, 64k mi. (bought 4 yrs ago, put 18k mi on it). Had 60k mi service May 2003, incl. flush/fill tranny. Tranny started slipping in Jan 2004 at hwy speeds; discovered fluid ONE QUART LOW! Put in fluid, everything fine, took back to mech who did 60k service for checkover, no problems, no leaks (have checked since, no leaks). April 2004, w/ac on, at hwy speeds, tranny slipped (revved slightly on tach, no increase in speed). Mech can't reproduce, can'd find anything wrong, NO CODE in computer! I've seen a number of posts about Tahoe tranny problems. Any suggestions? (Sell or invest in $2500 to rebuild tranny?) Thanks for help!

Are you still losing fluid and seeing no leaks?
A couple senerios here.
1. the transcooler is leaking..trans fluid is mixing with the coolant (coolant is mixing with the trans fluid)...usually you can tell by trans fluid in the radiator and overflow container.
Dexcool can wipe out a trans pretty quickly..starts with wiping out the torque converter clutch causing a slip in lockup...usually feels like a surge around 40mph.
2. Bad torque converter...slipping
3. sticking tcc apply valve...usually you get a SES light with this one and a code 1870
4. Flushing the trans...don't really like doing this when the vehicle gets some age on it...sometimes that dirty fluid is all that holds the trans togather...remove all the dirty fluid and put in 10-12 quarts of new..strange things start to happen.
just some thoughts

[laynel]

Thanks for the quick response!

1. No, checked coolant first thing -- it's clean. Trans fluid still full, no leaks (wonder if they put in enough when they serviced it to begin with??).
2. Could be?
3. No SES light, no code in computer.
4. Yeah ... I've never wanted to flush & fill trans either, but husband suggested full 60k service incl. trans service.

I've seen lots of posts about Tahoe trans problems -- so is this that common?

[GMMerlin]

Originally Posted by laynel

Thanks for the quick response!

1. No, checked coolant first thing -- it's clean. Trans fluid still full, no leaks (wonder if they put in enough when they serviced it to begin with??).
2. Could be?
3. No SES light, no code in computer.
4. Yeah ... I've never wanted to flush & fill trans either, but husband suggested full 60k service incl. trans service.

I've seen lots of posts about Tahoe trans problems -- so is this that common?

Tahoe is one of the most popular SUVs out there. it has a 4L60E transmission, same as most rear wheel drive GM vehicles.

[rjheard]

I used a product called LUCAS STOP SLIP in an Acura RL that had a transmission that was slipping BAD. It would barely move unless you drove it like you were 70 years old. This stuff made the transmission shift like new. I used two bottles and after about six months traded the car for something else. I would use this again in a second.