A year or so ago I made a bunch of rear suspension changes including a new Tarett sway bar and Elephant spring plate polybronze bushings. I did this for performance reasons but also because I was hoping to tame an annoying scraping sound coming from somewhere in the suspension. After a couple of months of driving, the scraping sound was worse and I had actually added two annoying new noises! One sounded like someone was occasionally tapping my behind-the-seat rollbar loudly with a hammer; the other was a persistent new mechanical creaking. I’ll spare you the tedious details of my search but they consumed a lot of time, pulling the shocks, disconnecting the sway bar, etc etc in an effort to put things right.
The hammering on the sway bar turned out to be the result of my poor installation of the Tarett sway bar. It was simply not lined up well enough to rotate smoothly in its mount when tightened into position. I ignored the instructions and assumed that it would rotate easily when the car was on the road even though it could almost not be moved with a short wrench in the garage! The clanging sound was the bar binding in the mounts, then occasionally snapping loose to rotate to a new position.
The creaking sound was revealed to be my too hasty installation of the Elephant Spring Plate bushings. Elephant’s directions are quite clear on what needs to be done to install these. You do need to measure how the bearing assembly fits on your car and shim it out at its four mounting points so that it sits 90* to the torsion bar with .050” or so clearance at each end. Cut this part of the install short and you will probably have to redo it later to get everything right.
The horrible scraping sound turned out to be the difficult-to-access center control arm bushings. This was found by spraying most of a can of silicon on the bearings then taking a test drive… the silicone kept the noise at bay for 20 minutes, enough to suggest that I might be onto the problem. There is much conventional wisdom here and elsewhere suggesting these bearings don’t ever wear out. Well it is wrong and they do. My car’s bearings, 40+ years old, were toast. When I pulled the first control arm out, shreds of what was left of the stock bushing fell out on the ground. A new set of Elephant sport bearings fixed everything.
I hope this helps someone trace an annoying rear suspension noise. I also hope it encourages everyone to actually pay attention to the instructions that come with these products. If I had actually followed these, two of my three problems would never have happened.
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