Poly Bushings issues

That makes a whole lotta sense, especially since the rubber pivot has that ball instead of a cylindrical stop. The ball probably fits into a socket in the rubber bushing, but when you put a poly bushing on it, there is no socket, and all the force tries to wedge the poly bushing over the ball. that'd make a hell of a racket, and probably shorten the life of the poly bushing considerably too.