One problem related to power train driveline has been reported for the 2008 GMC Sierra 3500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 GMC Sierra 3500 based on all problems reported for the 2008 Sierra 3500.
My 2008 GMC Sierra 3500hd has a chatter when turning, gm is aware of the problem and has a bulletin for a repair, however the repair may or may not completely solve the issue it didn't on mine. While turning the rear axles stays in a lock position and doesn't allow the rear tires to turn separate speeds this can cause the vehicle to go into a skid without notice and they set front and rear tire pressures different and the door stickers confirm that this is like driving a 4 wheel drive with small tires on the front and big tires on the back. Not only does this cause driveline failures but also could become unsafe and cause a loss of control. I have spun out more than once while turning at low speeds and once was on the way home from the dealer after the service manager told me it was fixed he "drove it himself" it has ruined the tires and now they are rebuilding the rear axle with only 25000 miles on it.