Clunking is a normal characteristic of GM 6 and 8 speed transmission. Its all computer BS programming to achieve fuel economy. That’s all the matters when building these trucks, make them as fuel efficient as possible even though they may drive like crap. Your driving a computer program.
Mine (15 Denali) still clunks (8-sp) after 35,000 miles. A good friend is in service management at GMC/Buick/Cadillac Dealer. We were talking a few months back about the clunking and he commented, if I had a $ for every customer complaint about clunking, I would be a rich man. Its the way they are.
