I noticed that when I go over medium to large irregularities in the road, it seems as if the rear is bottoming out. It feels and sounds horrible. Have you heard of this? Everything is tight and installed correctly. I am lowered on Progress springs on stock shocks (I know, I bounce). Before the install, I had no rear noise whatsoever.

 

it is normal.. I have the stillen rsb and it maes a noise.. better get used to it.......

 

Do you know what causes it?

 

move the passanger side axle bracket out a little bit. it will fix the problem.
the problem is caused by that piece that connects to the axle and pivots. the right side of it (in the pic) comes down and knocks against the bracket

 

Thanks for the heads up!