I officially think

[Donnie Yukonie]

There was a TSB with a updated nickel plated slip yoke or somethin that was suppose to fix acceleration from a stop clunk. Damn thing is expensive though. I just greased mine good.

Not that it matters for me anymore but do you have the TSB code?

 

[2000tahoeZ71]

Get underneath it and grab the driveshaft where it enters the rear end. Push it up and down and see if there is any play in the pinion bearing. My truck had kinda the same things going on and I caught it too late after the pinion bearing failed and ate my ring gear.

 

[qukon 95]

yhea i did that no play in it but i will see if it's the rear sway bar bushings.