I have been driving a 2011 2500 4x4 truck for work. It has developed a violent clunking during acceleration and I can't seem to locate it. The truck will not do it cold even with a heavy load. It will consistently do it when everything is hot, usually after driving down the highway then doing some stop and go driving. I think that is a clue? Its very hard to say if it front or rear, but it bangs through the whole driveline when starting to accelerate from a dead stop or slow roll. It doesnt take much power to happen, maybe over 20% throttle at least. The whole truck lurches when it happens, it will bang mabye 3 or 4 times in a couple seconds then stop when i speed up.

I have checked every u joint, they are all new enough to still be shiny, previous owner had replaced. Today I pulled the cover off the rear differential expecting to find metal debris, but the fluid was clean with no metal.

I see ones side of the rubber part of the transmission mount is starting to peel away. Shaking the transfer case, i can make it move mabye an inch? I had someone hold the brakes and give it throttle while i watched the driveline, it doesnt seem to move very much if at all.

Tommorow i will drain the transfer case, which i just had rebuilt a couple thousand miles ago and look for metal. I plan on draining the front diff as well.

Could this just be limited slip chatter? I know this truck has the 11.5 AAM with a LSD.

I planned a 4 thousand mile trip thats a few months away, i want to make sure everything on this rig is solid!

Thanks for the help anyone!