TruckGuy40165

I am glad that I found this site. I am a Chevy guy with a dozen trucks from 1947-2008. My main focus is 1955-59 Chevy Apache trucks, I have several. My question is about my 2008 Chevy 2500hd two wheel drive truck. The 6L90 was bad and I put a 2016 6L90 from a 3500 express extended can in it. It will not shift out of 3rd gear. Can I just have a GM dealer reprogram the transmission, or do I need a 6L90 out of a different truck. I have another 6L90 sitting on the bench, but I do not know what it came out of. Any help would be greatly appreciated. Karl [email protected]