I have a Perrin rear sway bar / endlinks, and progress springs. Other than that my suspension is stock. Yesterday, I adjusted my sway bar from the middle setting, to full stiff. After doing some hard driving, I noticed that when my back wheels go over bumps, there is a large clunk/grind type of sound. I have checked the endlinks, and sway bar mounts, everything seems fine. Could one of the rear springs have rotated when I jacked the back end of the car up or something? Any sort of insight would be appreciated.