have 99 tahoe 4x2, 5.7 liter, Automatic, 96k. On acceleration from stop and feels like body shifts and a slight THUMP or CREEP noise. Initially feels (symptom) like motor or trans mounts broken, and same occurence when coming to a complete stop. As if the powertrain moves before chassis???????. replaced ALL MOUNTS with new from dealer, Brakes in rear, new, u-jouints snug, body bolt & bushings OK, driveshaft has {((To-me))} too much travel (Accelerating with brakes Floored) from a quarter to a third of a rotation. Has anybody experienced this problem, I can't discribe it any better, but going out of my mind. It's been an ongoing problem and trying to resolve this is driving me and my honest Mechanic nuts. PLEASE HELP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

thank you
Lee

The same thing was going on with my '99, felt like I was carrying a load in the back that kept shifting when I stepped on the gas. I posted the problem on this site and got a ton of responses. Turns out I just needed to flush the transfer case with and replace the fluid, I think it was called Autotrak fluid....cost $16, heck of a lot easier on the wallet than replacing U joints, etc. Ran like a charm after that.

My 99 4x4 tahoe has a simular problem. It was a recall item in 99. There was a problem with the yolk. It think it was lubed but not replaced.