I have a '00 Tahoe 4WD. I installed new Monroe Reflex shocks a little over a year ago and have about 16,000mi on them. Recently, I've been hearing a notable rattle sound when going over bumps. I pushed on my rear bumper and was able to duplicate the problem. The upper shock mount on the right rear side appeared to be worn out already. I removed the shock only to find out the rubber bushing and spacer was fine. Upon further investigation, I saw the shock attach point on the chassis appears to have bushings installed and were elongated. My questions are these: Are there really bushings installed or has the spacer on the shock just wore an imprint on the mount? Also, do you know where I can go to get the part number? I've looked all over different parts sites and can't seem to come up with anything.