Did a search, while there was a ton of results, none really helped.

I'm starting to get a clunk from the rear end. It usually starts after making a turn at slow speed, but after that any time the car's moving slow I get it. Its a heavy clunk, meaning very noticible and affects the movement of the car. It happens approximately every 1/4 revolution of the wheel.

Any ideas? I took a look at the brakes and didn't see anything wrong, and there was nothing obviously wrong with the diff, no metal pieces sitting in the bottom of the housing, but of course I'm ruling nothing out.

 

Check for loose Lower control arm bolts, well loose bolts for that matter, one of mine was loose after i swapped rears, and it made a clunk.

 

Nope, that wasn't it, thanks though.

Now there's a higher pitched clunk that accompanies the original. Tried standing on the brakes while giving it gas and the sound was still there. Also, I forgot to emntion this the first time: the clunking only starts after I drive a while. If I try to reproduce the clunking leaving the driveway, it doesn't happen. Come home and pull in at the same angle once, and the clunking starts.

TIA

 

I had the same exact problem, turns out rear end fluid didn't have the special GM POSI additive, so I went to GM and bought this little bottle, poured it in and I never heard the clunking again.

 

My brother had the same issue. additive stopped the clunks.

 

Thanks guys. Apparently I didn't add it when I refilled the rear. Which means I probably threw out a full bottle of additive.