1994 XJS :

I have a loud noise coming from the rear end when I turn. The best I can describe it is a wobbling sound. It stops when I pull out of the turn. Its pretty loud and concerns people who are driving with me. They get scared. I've grown accustomed to it, though it is annoying.

Anyone else have a similar issue? Could it be the differential fluid? It seems to be coming from the passenger side.

 

At first guess I would say LSD clutches. Mine shuddered with the 2.88 XJS diff on tight turns, it was just a very tight clutch pack in the diff. Since I replaced the hemisphere with an XJR it does not do this any more.

It really depends on the type of noise you are talking about. The tighter the diff ie the less slip the harder it will be even to the point where the inside wheel will screech around a turn. If it bothers you go and have a diff guy check it out.

 

I think you are right about it being LSD related. Would maybe using a specific fluid help this? It seemed to get worse a few months after I changed the fluid a couple years ago. I used an LSD additive with Master Pro Gear Oil 75 90 GL-5.

Not sure what you mean by hemisphere. Googled it but did not find anything. I'm assuming you mean a part internally in the differential.

 

The hemisphere is the main part in the diff, you guys in the US call is a carrier.

I use an Australian LSD oil called Penrite very good oil and best part it is pretty blue and has the LS additive already in it.

It really depends on the type of noise you are talking about and if it is only on tight turns or if it on slight bends.

 

If it's happening only when you do tight turns then the LSD would be a chief suspect. Changing to a synthetic gear oil would be a good thing to try first. Also when you drain the current oil, make sure to check the magnet on the drain plug. If you see lots of metal bits that would be a sign that you need to inspect the diff gears.

If the problem is happening at speed and even at slight to moderate turns, like taking a fast bend or quickly changing lanes etc. and is happening only on one side, then it might me a load issue so check wheel bearings, diff output shaft bearing and u-joints. Also check rubber suspension mounts and suspension bushings.

 

If it is a loud but not a 'heavy machinery' noise, it is worth checking to see if those rubbishy universal joint covers are fouling something. Just a thought. If they are there, I think it is a good idea to remove them completely, anyway.

 

I had a howling noise from the rear end when I would turn hard left or right at low speeds, like in a parking lot or making a U turn. It was pretty loud and a little embarrassing. I took AllanG's recommendation and asked my mechanic to replace the fluid in the LSD to a synthetic. My noise is gone! Many thanks to this forum (another problem solved) and a special thanks to AllanG.