My rear suspension is creaking . Worse in the recent hot weather ,.I can sit on the rear bumper and bounce the car up and down often without a sound but then sometimes as it settles after being turned off , it lets out a creaking sound. I've sprayed the bearing areas with WD40, chain lube etc and it stops for a few days Is there a test for worn bearings ? With the car jacked up and the suspension on high , I'm guessing the radius arm is under too much load to detect any wear Where's best to get the bearing kit?