I have a friend with an 02 duramax and he's having a problem were the transmition will slip while drag racing in the 80 mph range. Then it slips durning shifts. If you turn it off and let it sit for a minute it will be just fine. He has a banks programmer and dynomax exhaust.

 

so whats your Question? What its doing is Limpine the transmission. the Allison has what they call a "limp mode". When 5th gear has to much HP going to it at once the transmission will automatically go into limp mode. When it does this it automatically shifts down to 4th and stays there until you reset it.(turning the truck off for a minute and turning it back on).

This feature is put on there to help you to not hurt you tranny.

Did that answer your question?

I would say that you buddy needs to turn down his programmer and then race or keep it where it is and keep his foot out of it until he goes out and buys some type of tranny for his truck. I am getting a Suncoast IV from Suncoast Convertors Inc. but im purchasing it through Inglewood Transmissions in CA. Heres the link of the guy im getting it from http://www.inglewoodtransmission.com/

tell your biddy to give him a call or go to their site, they have very good prices on all their stuff.

Thier you go thats about all i can tell you about this ut you could also go to dieselplace.com and register their and search the forums there for this problem. their are alot more and informative threads their on this subject you are wanting to know about, and also some more options for a transmission.

Thanks,
Dwayne