Hi all,

[xposted alt.autos.bmw,uk.rec.car.misc ]

My 1994, E36 320i Coupe suddenly developed significant vibration in the
rear axle. (hear cries of - "I told you so..." )
It only occurs when the transmission is fully engaged and accelerating .

If coasting - nothing.
Rev engine with clutch dipped - nothing.

The frequency of the vibration is related to the gear and current speed.
Low when pulling away. High when doing 40mph and acceleration or going
up hill.

If I drive down a narrow built-up road with the windows doen there is
not much difference in noise level - suggesting its travelling up
through the chassis.

My local garage looked at it and identified the vibration can be felt
under the back seat. However, after checking the axle was "safe" and had
plenty of oil - they suggested I drive it around for another week or so
and then bring it back in, and hopefully the source of the problem will
be more identifiable.

I'm worried that something may go horribly wrong in that time. I suspect
its their usual response when they dont want to spend TOO long looking
in the wrong place for a problem.

I suspect something is warped or rather loose and shifting under the
strain of load.

Any ideas?

Oh it seems the rear axle had already been replaced and it had yellow
chalk marks underneath  covered in grime.

I may try to nip it into another chap who always worked wonders on my
previous car but always wanted cash payments and his shop was really
small and surrounded by no parking zones! PITA parking 200m away and
walking to give him the keys!