Name That Noise

[ted280sl]

When coasting between 15 and 30 miles per hour my car emits an annoying squeaking sound. If I give the car even a bit of gas the sound disappears. I have a manual transmission and this noise appears regardless of wether the transmission is engaged. I believe it could have something to do with my rear axle but, I thought it best to seek expert advice before I start taking the car apart.
Thanks,
Ted 280SL w/ an unwanted squeak

[waltklatt]

Ted,
Might be time for the annual de-vermination of your pagoda. Wink!
Think it might have to do with the clutch bearing going out or being dry.  Drive shaft center bearing, or the rear end.
Why not put your car up on a lift that will keep the rear wheels free to roll and then have a tech sit in the car and engage the drive to see if one underneath can detect the protesting mouse.
Walter Klatt
1967 220SL-diesel
1963 230SL-gas

[J. Huber]

Hey Ted. Please consider Walt's stuff first. However, is it a very high-pitched chirpy squeek? If so, it might be the wheel bearings. I only know this because I played "name that sound" here about a year ago. In my case, this sound suddenly appeared while on a longish curvy drive. I heard it when coasting about 25-30, but it disappeared on acceleration. I really don't know if it was bearings -- because it stopped making sounds the next time I drove it! But thats what the experts here suggested.

James
63 230SL

[ted280sl]

Vermin? No that was definitely not the problem. I was thinking the rear end. I removed the filling plug and I was unable to feel the differential fluid. I added 1.5 litres. I am sure that will make a difference. While I was there I also greased the rear end grease points. It took quite a few pumps until fresh grease was squeezing out of the joint. I am sure this will solve my squeak.
Thank you for your help.
Ted  1969 280SL (- one more noise! )

[Vince Canepa]

Added 1.5 liters?  The filling capacity is 2.5 liters.  Were the axle tubes horizontal when you topped it up?

As for the grease points, they would sqeak when you compress the suspension (over a bump, bouncing on the rear bumper).

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[ja17]

Hello Ted,

Try swerving the car from side to side while driving to see if the noise changes or goes away.



Joe Alexander
Blacklick, Ohio

[jeffc280sl]

I just found the source of a high pitched squeaking sound in my rear suspension.  Turned out to be the rubber bushings on the cross strut.  I recently installed a refurbished 3,27 raio axle with all new rubber bushings except the cross strut bushings on the frame end.  I thought they were in good shape so and I didn't want to mess too much with the geometry so I did not remove the frame side of this strut. I must have turn the strut during the install of the new axle such that a weathered area of the bushings ended up rubbing together.  The squeaking occurred with small vibrations up and down when the suspension was loaded.  When one side was jacked up the noise was gone.  It also was evident when driving the car on regular roads and swearving side to side.  One direction caused the noise while turing in the other was silent.

In order to find it I eliminated other sources near the noise.  This included the exhaust system, passenger side rear springs, pads and brake assembly.  This means I took these items apart or removed them to take them off the list.  Eventually I narrowed the culprit to the cross strut.  I could change the pitch by holding on the the strut end and shaking the car side to side.

Ended up lubing the rubber bushings very well and then pushed the car side to side and up and down so the luricant could find its way to the dry area.  What a pain, but I'm glad to have found it!

Jeff C.
1970 280SL 4-speed

[nick350]

I had a constant squeeking from the back of the car and after some investigation imagine my suprise when I found a family of mice had moved in...........how we laughed.

Nick350
r107 SL red
w113 SL white

[seattle_Jerry]

Jeeze sometimes I wonder about you guys...when there is such an obvious solution to the problem. Don't coast between 15 and 20 mph

"Doctor it hurts when I go like this" "Well don't go like this"

Actually what I find interesting about your noise is that it occurs under no load. I had diff noise but it only happened while under accelleration. So does that mean that it is something that the torque of accelleration tightens, eliminating the squeek?

1967 230SL Havana Brown Auto with A/C