1995 S320 LWB Vibration

[krissyd]

Hi,

My S320 119500 miles is vibrating. It becomes very noticable between 60 and 85 MPH where it becomes a droning noise appearing to come from the rear. Only vibrates under load. I have had a 4-wheel alignment done. While the car was in the air I had a good look round - looks like fairly recent bolts on the propshaft coupling to the gearbox. Everything else looks quite tidy. Also new shocks all round and new NSF top ball joint and inner track rod end (hence the re-alignment). New spark plugs and all new coil packs as they all died at 118000 (its great limping home on 2 cylinders - NOT)
When cornering hard to the right under load the vibration can be felt as a knocking through the central armrest.
Car drives in a straight line and brakes the same.
Noise gets louder as the suspension is compressed such as driving over a large hump in the road.

I am thinking rear diff, propshaft out of balance or rear bearings

I need to service the car soon so any suggestions?

Also I live in Devon. Does anyone know of a rolling road which doesn't cost MB prices in Devon so I can get this checked out before throwing money at it.

 

[louisjames]

it sounds like a diff thing 2 me? or prop definetly. i had exactly the same thing on a 328 bmw, i had prop replaced, as more powerful engines have rubber rings around prop, andthey are alot fatter, and also diff replaced and cured it. but then between the speeds it hapens youd think it would be a wheel problem?

id say worth having diff checked out as a priority.

oh and ps, just thought, i also had same symptons on a 325 coupe bmw, it had limited slip diff, and they discovered that one of the diff carrier bolts had sheered and snapped, hence under load and certain cornering i got exactly the same symptons as yours....?

 

[krissyd]

thanks

I will take a look when i service the thing - waiting for the cold spell to end first. I dont fancy crawling under a merc when its minus 1 outside . brrrrrrrr