I have an 02' Dura/Allison combo. It's not shifting like it should. If you were to floor the accelerator from a dead stop, right when it gets to 40 mph it does not want to shift up. It's like sticking in third gear. I've taken it to the dealer and had the Park/Nuetral switch replaced and still had the same symptoms as before. Took it back to the dealer today and they told me it was low on trans fluid, the internal & external filters were replaced, and my air filter was dirty. And $ 420.00 later it still does it. Drove right back to the service shop and took the service mgr for a ride and was able to replicate symptom for him. He said to me "Give it a couple of days of driving and maybe it wll clear itself up; if it does not improve bring it back". Anybody out there have same problems? Truck is an 02' Duramax/Allision combo, Crewcab shortbed, 6" lift running 315/75/16, and has 92k on her. No mods to the engine that I know of and dealer has not found any mods. Could a previous mod that has been removed cause the shift problems? Any help would be much appreciated.:confused: :confused: :confused:

I would find a new servicing dealer that can properly diagnose your problem.A simple ride with a Tech II should suffice.

Interesting you don't mention it was scanned for possible codes

Mine is doing the same thing. Have you found the problem yet?

"Give it a couple of days of driving and maybe it wll clear itself up; if it does not improve bring it back".

That's when I would have said "Give my checkbook a couple of days and maybe it will write itself out your $420.00 check." :D

I hope it works out for you. Nothing blows more than spending money for some doh-head to turn wrenches on your truck and not have the problem fixed! :mad:

http://dieselplace.com/forum/showthread.php?threadid=33623

I don't think there is anyone in Reno NV that knows much about the Ally. I am very friendly with the 2 biggest shops in town and they have not seen one yet. Get a Tech 2 on your truck and check for codes. Good luck.
mike

on our 02 dura/ally it woodnt shift into 4-5 and from 1-2-3 it was real hard and we replaced a black box on the side of the transmission for 137$ and it fixed it. they said road debris break the plastic and then dirt gets in there and screws it up.