Rear clunk e36 not suspension!!

[Max55]

Hey guys this sound is driving me nuts and I cant pinpoint it at all. It sounds like a mix between clunking and binding. It happens regardless of whether im in gear or not or accelerating or decelerating. It is definitely not related to the suspension because i can driver over bumps and turn the car all day and it wont make it. It seems to be coming from the driver side rear wheel area. All lugs are tight, ive felt ever part under there and everything is solid.

It happens primarily only when driving slowly, speeds below 40. It doesnt always do it, sometimes it will do it a lot, somedays not at all. When it does do it, it sounds like "clunk. .clunk clunk, .. . .clunk . . ... . .. . .clunk clunk" all while driving between 15-50. It might be doing it at higher speeds but road noise makes it less noticeable.

The car has 150k on it and does seem to have been neglected somewhat. I took it to some german shop before the noise started and he drove the car for 1 minute and said " the diff is failing" since then i have driven over 2000 miles. and its exactly the same. the clunk started not long after taking it there. There is oil on parts right at the end of the driveshaft, in front of the diff, which doesnt make any sense. Help!! please!!

[Critter7r]

Binding rear driveshaft U-joint? Unbolt the u-joint and see if it is smooth in all directions, there's likely a flat spot in it.

The oil on the diff is probably just the front seal leaking and the spinning prop shaft is slinging oil around.

[Doc325i]

I would suggest to double check your rear trailing bushings.

[Max55]

ok, I will have to get under there when I have some time and its light. It just did it all the way home at all speeds, straight line driving and turning. Is the car safe to drive?? you can feel the clunking sound through the floor/pedals

[speedster]

trailing arm bushings...

wheel bearings....

[thejlevie]

Differential, bad half shaft, or binding u-joints in the drive shaft.

[Doc325i]

I know you've ruled out the suspension but i would take a good look at the rear shock mounts also.

[Max55]

Hey guys, first of all, let me thank the member of this board for trying to help so much more quickly than some other boards I checked.

I took my car to a local shop with some real mechanics, and they fixed the problem. the problem was 2 fold, the wheel bearing was going bad which is what i think the other German auto shop thought was a bad diff(or they knew but wanted to get my wallet) Also the clunking noise was primarily caused by the rear brake pads being very very worn. Almost metal on metal. So 325$ later with new pads on both sides and a new wheel bearing, the cars 'clunk' is history. Now on to new issues!!!

[Ncaviation]

Sounds silly but... Is your exhaust rubbing on your rear axle? happened on mine and couldn't figure it out for quite some time