last night on the way home from work, I was rolling to a stop at a stoplight, no hard braking or anything, and when I was nearly stopped, it felt like the ally shifted down very hard. It did not repeat it self, however, but I have never felt this before. Truck is a 2003 GMC crew, short-bed, 4x4 D/A with almost 20k miles. Tranny fluid checked out Ok and spin-on was changed at 10K miles.

Any thoughts?:confused:

Clear and reset TAPs or just let it relearn on its own. Sounds like you still have a stock Ally. They will do this from time to time. Always a good idea to check for codes.
mike

thanks, Mike, I am still trying to convince my wife I need one of your tranny upgrades...trying to disguise a trip to Disney with the kids so that I can get some male hormones in Allison):h