[normharp]

I have an '86 560SL and am getting an oscillation from the drivers side front end as I hit 65 MPH whether the road is bumpy or smooth. If I stay at 65, it will come and go in waves. At 70 and above, it rides fine. I have switched the drivers front and rear tires without a change in symptoms. The tires were high speed balanced. The alignment is perfect. The car does not pull at all. The ball joints are in excellent shape. Has anyone changed shocks for this specific symptom? Thanks.

Normharp

 

[Stan Pugh]

Front end

You've got a good one! Mercedes has a test procedure to check the different shock absorbers, 32.1 - 120.

I was also thinking about the linkage and/or pitman arm - test procedure is to "shake it vigorously" to see if anything moves.

All electric motors and centrifical compressors go through a "critical vibration" stage on their way up to operating speed, kinda reminds me of that. BUT, your auto shouldn't do it.

It almost sounds like a faulty tire, but then that would have showed up during the high speed balance.

If you don't mind, and can remember, I'd appreciate on hearing what the fix is.

Thank you, and good luck,
Stan

 

[normharp]

front end

Stan,

Thanks for your quick response. I was planning on changing the shocks any way since I have no idea of their age.I will also check the pitman arm. I will inform you of the solution.

normharp

 

[Greg in Oz]

Wheel bearing?

I can remember some years ago having a subdued vibration or humming noise that occured at around 100km/h (62mph). It was difficult to pinpoint the source but it could be felt slightly through the steering wheel. Eventually I replace the front wheel bearings and that fixed it. The bearings had no obvious play or noise when rotating the wheels at low speed but obviously at least one required replacement.

 

[normharp]

wheel bearing?

Greg in OZ,

Thanks for the information. I thought about the wheel bearings but figured they would cause a vibration at lower speeds also. Obviuosly, from your experience, this is not always true. It will be a few weeks before I am able to work on the vehicle. I will let you know the results.

Normharp

 

[normharp]

Re: Front end

It turns out that some of the tire bands were out of whack causing the vibration. One tire in particular had a real problem I decided to change the set and the car is trackinga as it should. Thanks to all who posted suggestions.

Normharp

You've got a good one! Mercedes has a test procedure to check the different shock absorbers, 32.1 - 120.

I was also thinking about the linkage and/or pitman arm - test procedure is to "shake it vigorously" to see if anything moves.

All electric motors and centrifical compressors go through a "critical vibration" stage on their way up to operating speed, kinda reminds me of that. BUT, your auto shouldn't do it.

It almost sounds like a faulty tire, but then that would have showed up during the high speed balance.

If you don't mind, and can remember, I'd appreciate on hearing what the fix is.

Thank you, and good luck,
Stan