is your car lowered? you may be bottoming out....center of rear hitting the pinion snubber. jack your car up and look at the snubber, located just in front of the rear end housing hanging from the floorpan of the car. if it has been hitting you will see it. i have only seen this on cars with cut springs. let me know if you have any questions...feel free to e-mail me. PULN_AWAY@MSN.COM