Rear end knocking sound (1991 BMW 318i)

Hi,

OK, first off, the car is a BMW 91 318i, e30 chassis (86k) with 4.10 LSD. I just had the bearings in there replaced, as it was whining. What happens is if Ive been driving at speed, and then go around an offramp for example a bit too fast, or even ata resonable speed, Ill get a knocking noise fairly loud. It almost sounds like its coming from the transmission hump area in the rear seat.

When raining, Sometimes itll just happen as well (at least I think its the same sound), just from driving in a straight line.

I jacked up thje rear on both sides, and took the wheels off one at a time to see what is going on in there. One side (ds) which I thouhgt was noisy seemed fine. The other (passenger) side started acting odd right away. As soon as I started jacking it slightly, I heard clicking/knocking sounds similar to what I normaly hear. Also, I noticed that the wheel wanted to travel slightly (like normal rotation) from where it was, as the ension was removed. When it was completely up in the air, I noticed that the whole axle shaft will turn in a rotational fashion about 1/4 inch either way. The other side didnt do this. I am unsure if this has to do with the limited slip functionality or what. It just seemed quite odd.

I think the next step is to check the cv joints, as I am unsure if the play is similar, but to me it makes sense that going around a curve it may be easier for that wheel to relieve its tension, and so the axle's LS capability gives a bit, aking the noise (perhaps Im hearing the ls axle doing its job). Similarly, when driving in rain, if there is tension on that side, it seems to me that the presence of water could provide just enough slip that the tension is removed from that side and that side givesd making the sound from the LSD again. All the clutches, etc in the LSD are fine, I had a differential rebuilder check everything out by a full breakdown.

All rubber looks fine except the sway bar links, those bushings are a bit cracked, but they shouldnt cause a knocking sound liek that, IMO.

Thats my scenario...

Any assistance or suggestions woul dbe great.

Thanks,

JMH

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