1-2nd tranny issue

chadc77 · March 7, 2005

I have a '04 single cab 4x4 GMC. When I accelerate from a stop with the throatle position @ 3/4 or full, 1st -2nd gear stumbles. In other words instead of one shift it feels like there 3 parts to the shift. It tries to shift then stumble and then finally shifts. The truck has been @ the dealer for a week now. They have basically rebuilt the tranny. I test drove the truck this past Friday after the work was done and the issue was still present. The service manager is going to talk to GM about a installing a new tranny. ANY IDEAS!!!!!!!!!!!!! PLEASE HELP!!!!!!!!!!!!

GM-Tech · March 7, 2005

I personally don't repair transmissions. I help our tranny guy at times because while he knows the hydraulics and mechanics of every trans like the back of his hand, he's weak on the electronics side of it.

That said, I can't help you. If I had it right here in front of me and spent some time diagnosing, I'd say we'd find the problem and fix it. Since it doesn't appear to be a known issue, attempting to diagnose this over the Internet ain't gonna happen.

navs39 · March 8, 2005

I have 2002 Silverado and it was doing the same thing. Well I am not sure if you have had the problem fixed but here goes. Just in case you havent found a solution. After several visits to the dealers and many dollars spent I actually found a good dealer that was willing to work with me. As soon as I took it in the guy at the dealers said it was the WIRING (ECAS) JUMPER HARNESS. He explain everything my truck was doing with out me having to tell him what it was doing. All I had to say was I am have a problem with my trannny and he knew what is was. It was a problem they were having with some of the trucks. There was a bulletin out on the problem. Well i am not saying this is your problem but it is something to ask them about. Once they replaced that my problem went away. Hope it helps. Dealer are funny that way and wont give you the info you need.