Loud clank from rear end

[2001 GTS]

Its not the normal driveline slack clunk. About 1 out of 3 of every start from a dead stop...a loud clank comes from the rear somewhere. Sounds like something is hitting something...kinda sounds like a wrench hitting an exhaust pipe. Loud enough I can hear it echo in a parking garage! A few months ago the noise was happening every so often...and one of the half shaft bands had moved about 1mm out, giving one of the bearing caps a little wiggle room. Tightened it, and noise seemed to go away. Now again recently....its happening again. LOUD ASS CLANK!

Any ideas?

Thanks,
Steve

 

[99 R/T 10]

Check your U-joints right now to include all bolts associated with the 1/2 shafts!

 

[2001 GTS]

Ok, I got under there and looked. One of the bearing caps on the drivers side half shaft next to the spline is moving a good 1/8" in each direction..INSIDE THE CAP. So I guess I'll throw in one of these spare half shafts I have.

 

[Tom Sessions]

check the bolts taht hold the rear diff to the frame.I have found several of thes on 01 cars.Almost sounds like someone hitting the frame with a sledge hammer.The bolts that are on the outsid of thr frame rails go to 100 lbs/ft the two that go up through the dog bone also go to 100 lbs/ft and check the bolts on the dog bone.can't remember those right off.