Originally Posted by Aggiesrok
They could be loose. I think the upper control arm may be the problem. May have broke or busted a weld. It keeps rear end pinion angle correct.
I agree it sounds like a worn out bushing allowing extra free play. Make sure to check all the bushings in your whole suspension too. If one is old and worn out, chances are there's others on their way out.
Pinion angle is very important too. Make sure you get your adjusted at your earliest convenience at the very least.