I have installed a Pro-thane Total kit in my 04 Z and I have been having a clunk in the rear ever since I installed it. I have found what could be the problem. On the rear, rear sub frame mounts, the ones closest to the muffler, there is approximately an 1 cm space between the top of the bushing and the frame of the car. The bolts are torqued to spec so that rules out that it is loose. Anyone else with the pro thane or other rear sub frame kit have this gap? Thanks for the help.

 

You sure the bushing is seated properly?

 

There is only one way it goes on so yes, unless the directions were wrong and the top and bottom needs to be flipped.

 

Does seem to be coincidental that there is a gap, and that the bottom is thicker.
I'd just contact Prothane and send the photo as well.

(I have their other bushings and no problems here, very good!)