pvknight

Installed Bilstein Sports on the FRC about 3mo ago and the driver's rear shock has developed a high pitched, super sensitive (to changes in the road) squeak that you can hear 100% of time. Unless, I'm in a hard right turn in which case the driver's rear shock is fully compressed and quiet.

What the heck would cause this? I cleaned, greased, and reinstalled the stock bushings with the new Bilsteins. Is it possibly not tight enough? Does the upper or lower bushing usually cause noise?

Any help appreciated, thanks

pvknight

update:

-Removed Bilstein shock, cleaned & greased upper bushing and mounting plate, tightened fully and reinstalled.
-Removed, cleaned, and greased rear swaybar bushings.
-Cleaned and greased upper and lower a-arm bushings.
-The very last thing I can think of are the swaybar endlinks, which I will change tomorrow.

The squeek sounds like it's coming from the shock or very near it. The sound follows the travel of the suspension and detects even the smallest changes in the road.

Can a Bilstein Sport shock just start squeeking for no reason? There's no evidence of leakage.

Please please help, thanks.

Brian

Vette_Fan

Same here. Added the Bilstein sport shocks & Hotchkis sway bars. The passanger side rattles so much, it feels like the rear speaker is loose, or something in the rear window of my coupe is loose. But I know nothing is..... so gotta be the shocks/swaybars.... Now, how do we fix it...

pvknight

A rattle is most likely from the swaybars; aftermarket sways are notorious for noise. New and tight endlinks might help!

Mine is a suspension squeak that developed 10k mi after an otherwise good shock install.

mannn i hate elusive noises

Vette_Fan

Mine were a new set of Hotchkis sway bars, new endlinks, and new poly bushings. Its quiet sometimes, and sometimes very annoying...

ICaughtVetteFever

I remember something about needing to reuse OEM mount bushings as the Bilstein ones will make noise on some cars. I had them on for a few months before coilovers and I used the OEM bushings and never heard a sound.

pvknight

Thanks for the response. I did indeed reuse the OEM bushings and hardware, everything was in good shape and install was smooth.

Sound persists. Could it be the shock?

Are there other grease points that I need to know about?

RatedX

I put in Bilstein sports; and I put in new poly bushings on the zo6 swaybars, It has been absolutely quiet.

sigma6

+1 for Bilstein with oem bushings and has the squeak for years now. Never figured out what it was. I greased up the swaybars and put new endlinks, so that's not the prob.

My squeak also comes from passenger side rear. Too lazy to keep trying.

mchaskell

If you do not compress the shock bushings enough between the washers it will let the shock shaft rub against the shock tower. I found this out the hard way.

mph1972

I just turn up the radio.

sigma6

Interesting! Will check this out but can you clarify w/ pictures?

mchaskell

Inside the bracket (pictured) that bolts to the body is where mine was rubbing. I could tell because it had a shiny spot where the metel to metal contact was. I tightened down the bolt on the shock piston shaft to compress the bushings more and the squeek was gone.

sigma6

Just to clarify, is the bolt in your picture the one you tightened?

Uncle John

No, hes talking about the bolt that goes on the end of the shock absorber shaft. If the bolt is too loose the bushings will not be compressed tight enough to keep the shock from moving around on the bracket and may allow the shaft to rub up against the bracket that is sandwiched in between the bushings. The bolt on the above picture is one of two that are holding the bracket to the body of the car.

mchaskell

Yes...what Uncle John said .

sigma6

Ah, I know what you're talking about. The bolt that causes the entire shock body to turn when you tighten it. How do you hold the shock body still anyhow?

mchaskell

There is a flat on the end of the shaft. You put a wrench on the flat to keep the shaft from spinning while you tighten the bolt that compresses the bushings.

sigma6

Ah hah! you were right this was the culprit. Apparently, re-using OEM bushings is the cause, imho, because they are not as thick as the bilstein supplied; And as such, the compressing nut can only go down so far but not quite enough to compress the oem bushings enough, so the bushings move around. Therefore, my advice to anyone else is to not use the oem bushings (rubber things) with the bilstein shocks.

pvknight

Thanks for all the input guys.

My update: I took the car into LA Performance Div. and took a long test drive with Al. He heard the sound too and suggested taking another look at the upper mount. Sound persists.

The above reply about the stock bushing being too thin and allowing movement makes some sense. When I took the mounting plate and stock bushing out, there was some wiggle room. Still, the bushing looked like it was doing the job. I just cleaned, greased, retightened and installed and there was no change in the sound.

P.S. To add to this, just now, my suspension developed a VERY loud clank and knocking noise that is unrelated to my original problem. Could be a broken end link or something? Certainly puts this small squeak to shame.

Go GM.