Squeak

[Rick007]

Dear Forum , please advise ...
I have an irretating squeaking noise wich is driving me crazy .... The symptoms :  When cold after start up : nothing . In stand stil : nothing .  After a 10 minute drive and things heat up, a high pitch squeaking noise , which to me sounds like suspension related , because its only heard when going over a small bump . At first you think its a exhaust rubber wich is dry ....or a dry rubber bushing .  On a flat and smooth road : nothing
But as soon as i hit a ruf road surface the high pitch squeak returns .... especially when you drive throuh a village and the sound is reflected from the buildings you pass

What have i don so far :  Replaced everything on front and back suspension ...everything is overhauled . New springs , shocks , rubber bushings , axle bearings ( the good ones ) , exhaust with mountings , replaced the trunk-mounting .. Tried to lubricate all the new rubber bushings ...still it returns .  aaaaahhhhrrrr     this is so irritating .  What have i overlooked ??

Could it be, that after replacing the rear axle bearing ( the one on the right hand side , because it sounds like its comming from that side ) that after warm up the brake pads squeak against the rotor ? I'm not sure but it looks like the noise is gone when braking   And i hear nothing when cold ?  Before i tear down the axle maby you guys can give me some pointers on things i might have overlooked ....

Gr. Rick 

[w113dude]

is the noise constant or only when you go over bumps?

[Rick007]

Thats whats puzzeling me its only on a rough roadsurface . And also i cannot reproduce it when standing still . Moved the car in every direction possible , up and down on every corner , sideways ...nothing .
But as soon as things heat up and i hit a bumpy road ...there's that squeak again .....annoying to say the least .

[Larry & Norma]

The steering idler arm use to squeak on my car, but only when it was hot
after a few miles driving. Replaced the plastic bushes and all is well.
Your squeak does not seem to steering related

[Neil Thompson]

Rick my brakes squeal when hot, as you drive along with the noise present, with nothing behind of course press the brake pedal slightly with your left foot, if the noise stops its just the discs and pads slightly touching which is fairly normal, de glazing the surfaces with sand paper or similar will eliminate but just for a while.

Neil

[w113dude]

To eliminate possibilities I would jack the car up on stands with the wheels spinning or better yet on a car lift, i have heard some noises in the past that comes from the drive train. maybe a transmission bearing?

[Rick007]

Yes i know Neil ,the brakes can sqeual a bit after heat up .  Last year i found that after my axle rebuild the 2 bolts which  hold one of the rear calipers came a bit loose , even with the metal securing-tabs folded .  That explained the thumping noise going over speedhumps .  So one new disc and pads solved that ...  ( Proofs that after a full rebuild always check and tighten after a couple of Km / Mls )  And now with some coppergrease on the back of the pads i'm squeel free ......so far the brakes that is.  But this squeak is persistend ... And only going over a rough road-surface , high pitch and not regurlarly . 

Had my car on and off the lift all the time , wheels free , wheels on the ground .  One time i had it on the carlift , wheels of , and with the air-jack under the rear diff and just let i bounch up and down a bit by triggering the air-jack  ...no luck and no noise . Wheels on ....same thing ..  On the road ....after a while ( thinking its gone   .. and there its back again .
 
I really don't know anymore . My wife says i'm over sensitive about this noise and i should ignore it .... wife talk :" just turn up the radio so you don't hear it anymore" ..yeah this helps dear thanks 

After all this searching and tryiing it must be something to do with the springs or bushings ( all new and original MB btw ) , so loosenig it all up and use some teflonspray is my next move .
And since i have to be under car anyway because all this searching and crawling under the car did reveall a small leak in my radiator....pfffff good thing we really love these cars .