Vibration/Humming at 50-85mph on 230E W124 Auto 54k miles

[merc230e]

Hi all, I have the following problem with Vibration / humming - revolution based at speeds from 50mph to 85mph approx.

I first thought front wheel bearings - replaced these. Wheels, tracking and balance checked. Still there.

Removed propshaft. Replaced front flexi coupling, replaced vibration damper. Replaced centre support bearing, rear rubber coupling and has the shaft balanced. Problem still persists.

Also drained the backaxle and refill (no swarf). Replaced the moutings for the backaxle and fitted a vibration damper via the mountings, still no cure.

Has anyone come across this problem before? Any thoughts or suggestions would be greatly appreciated.

Many Thanks.
Dave

 

[jberks]

How old are your tyres? - I'm guessing with that mileage you don't change them quite as often as I have to!
A warped or out of shape tyre could do it. It should have been picked up on balancing but sometimes they simply balance it out, but the contact on the road still won't be right.
I had a Granada do the same thing a few years ago. Cause was a broken gearbox mount.

The only other thing that comes to mind is fan coupling (if you have one), but then it will do it in neutral too.

 

[merc230e]

Thanks for the info. Already replaced gearbox mounting, new tyres, balanced prop.

Cheers for taking time to answer anyway.

 

[kth286]

Dave

Where is the vibration - through steering wheel or felt under drivers seat ?

Is the car new to you and has vibration been there all the time ?

If car is not new to you, how did vibration first start ?

Is the problem getting worse or staying the same ?

Has any improvement been felt after doing all those jobs on the car ?

Were the rear tyres also balanced ?

Are the tyres wearing evenly ?

Does the vibration or humming differ when going around corners, either left, or right ?

If the car is static and you rev engine, does vibration occur ?

If you manually hold gear in say '2and' position and drive car, is it the speed of the car that causes the vibration or the revs at which the engine is turning ?

Answers to these questions should reveal more likely causes.

Regards