Caveman90406

Hi there, I have a 2004 2500HD Silverado 6.0 Gas Crew Cab. I just bought the truck from a dealer in town and the transmission went out barely 24 hours after I drove it off the lot. I took it back to the dealer and they rebuilt the transmission, new water pump and new radiator. After I got it back it seemed to run fine until i got on the highway, when i get to about 55mph-70 mph on flat ground with empty truck, it will not shift down. It rides at about 3500 rpms, and will not shift all the way up to 5000rpms. The truck only does it some times, other times not. I havent figured out a pattern or anything. No codes, and transmission isn't running hot. I am thinking maybe the dealer didn't replace the torque converter? I confronted the dealer about this problem and they took it back for a few days to drive it and diagnose the problem. They came back saying that there is no problem and that 3/4 tons are geared that way, which i don't believe because i have driven 3/4 ton trucks of all kinds all my life for work, mostly GMCs and Chevys of the exact same model and none have ever done this. I would appreciate any advice or opinions on what it could be.


Thanks,
Ben

Caveman90406

Correction to that...the truck won't shift up. Not shift down, sorry.