rear noise
08-30-2014, 11:54 PM
#1
Burning Brakes
Thread Starter
rear noise
i have a noise in the rear of my z-51 coupe. i have isolated it to the single transverse fiberglass spring.
the lowering bolts have a rubber washer molded to the adjustment screw. the rubber "foot" contacts the A arm. the aluminum A arm has a flat pad area which this foot rests on when the spring is tensioned.
this pad to foot area becomes dry after awhile. if i raise the spring a little, i can wedge some grease in between the pad and foot which silences it for a few weeks.
when i originally lowered the car, i had to remove some thickness from the rubber foot to lower it enough. this mod is well documented. eventually, the thinned rubber wore out, causing metal to metal contact.
next, i went to custom delrin bolts from Hardbar, a suspension company. the owner told me to add grease when installing them. he also developed an improved version later, which he sent to me at no charge. still, the noise persisted after about a month of driving. he told me that the factory bolts that i had ground down may have made the A arm flat pad rough from metal to metal contact. i then removed the entire spring from the car and although they did not look very bad, i sanded the pad area down with a fabric brush that you can attach to a die grinder or hi-speed drive. both A arm pads were very smooth and almost looked like polished aluminum.
after re-assembly, the noise returned in a few weeks. it is a bit of a pain in the *** to have to grease these and some of the grease ends up in your driveway and garage.
next, i tried some aftermarket, stock appearing bolts from a corvette supplier, maybe west coast corvettes. these make the noise as bad or worse than the high quality Hardbar delrin coated bolts.
i would try the stock factory bolts next, but GM, in their infinite wisdom, only sells them along a new, expensive, fiberglass spring.
has anyone else experienced something similar?
thanks
the lowering bolts have a rubber washer molded to the adjustment screw. the rubber "foot" contacts the A arm. the aluminum A arm has a flat pad area which this foot rests on when the spring is tensioned.
this pad to foot area becomes dry after awhile. if i raise the spring a little, i can wedge some grease in between the pad and foot which silences it for a few weeks.
when i originally lowered the car, i had to remove some thickness from the rubber foot to lower it enough. this mod is well documented. eventually, the thinned rubber wore out, causing metal to metal contact.
next, i went to custom delrin bolts from Hardbar, a suspension company. the owner told me to add grease when installing them. he also developed an improved version later, which he sent to me at no charge. still, the noise persisted after about a month of driving. he told me that the factory bolts that i had ground down may have made the A arm flat pad rough from metal to metal contact. i then removed the entire spring from the car and although they did not look very bad, i sanded the pad area down with a fabric brush that you can attach to a die grinder or hi-speed drive. both A arm pads were very smooth and almost looked like polished aluminum.
after re-assembly, the noise returned in a few weeks. it is a bit of a pain in the *** to have to grease these and some of the grease ends up in your driveway and garage.
next, i tried some aftermarket, stock appearing bolts from a corvette supplier, maybe west coast corvettes. these make the noise as bad or worse than the high quality Hardbar delrin coated bolts.
i would try the stock factory bolts next, but GM, in their infinite wisdom, only sells them along a new, expensive, fiberglass spring.
has anyone else experienced something similar?
thanks
