Last summer, I swapped out the springs all around on my car. Used BBK lowering coils up front, stock '94 GT rears with overload airbags.
Ever since the spring swap, I have this weird clattering noise coming from the rear suspension when I go over bumps at anything above 10-15 mph.
The springs have polyurethane isolators top and bottom and are not loose in the spring cups. It's definitely not the exhaust hitting as it sounds like some sort of sheet metal clattering against something else. I looked all over back there and can't find anything.
Any ideas?
Check the sleeves on the rear shocks.
Check the nuts and bushings at the top of the rear shocks, too.
Did you check the rear swaybar bushings? That is of course if you have a rear swaybar.
There are no bushings on a factory rear swaybar.