I bought my car w/ Bilstein PSS9s but they use the OE upper mounting parts. I have been having a bad thump in the left rear going over certain kinds of bumps and I have tried everything inside to find and stop it. To no avail. I examined the spring mount and I saw that there is a torn rubber or plastic ring right at the top. Is it possible that the spring is banging up against the metal or even the bolts?

Whether or bot this is the source of the thump, is this a serious problem or just a nuisance? I track the car.

Bill/Memphis

 

FWIW this WAS the source of the noise. The cushion pictured was crushed and allowed the strut rod to move up and down. The noise was the rod hitting the underside off the plastic trim over the mount.