Hello, I want to start by saying thanks for all the information I've gained off of everyone on this site. I've referenced it alot over the last couple years. Now the problem, 92 bonnie 140k SE trans bangshift. Bought a used 4t60e with 76k on it, with the help of Bill Bittermore'* instruction, swapped it out, all went well. ran like a champ, smooth as silk, now it'* having a problem shifting from 2 to 3, just kinda hangs there. If your going downhill, foot lightly on the gas, at 30mph or so rpms will drop, and the trans shifts, uphill or accelerating it'* a different story, rpm'* rise until around 50mph, where it shifts or the tc locks up or both, drops to about 1500 rpm. If this has been covered on here and I missed it I apologize. Thanks again

Hey folks, it'* me again with an update. I,m guessing from the underwhelming amount of replies that that this is an odd problem, or an old one that'* been beat to death. Anyway, I took the old girl to my local trans shop, and the owner took us for a ride to experience the issue, and this is what he came up with. Third gear clutch piston seal is leaking, not letting third gear engage. No easy fix, other than pulling the trans and rebuilding. Sucks to be me... oh well good news is it should run like this for a long time, it'* not terminal, just shot my gas mileage all to hell. Hope this helps someone else who'* scratching their heads. I also found a site called scribed.com that has a gm manual for the 4t60e that'* full of drawings, parts lists, and flow charts. Here'* the link 4T60E Like I said I hope this helps somebody, and remember, bloody knuckles, rust in your eye, and laying under your car in your driveway in all sorts of weather are just the joys of motoring.

Bob,

Thanks for taking the time and posting the diagnoses. May help others with a like problem.