Hi All,

Sorry if this has been covered in the past, but my car has developed a whine from the diff when decelerating. When I purchased the vehicle (vehicle has 25k miles currently) I thought it was wheel bearing noise.

From what I have found, all 4.2 V8 XJ's and S-type's share the same 2.87 8" Visteon (Ford) differential. My car looks to have part number C2C34878.

From all my research it looks like all of them have been discontinued and no longer available. Multiple sources have also told me Jaguar/Ford never released internal drawings to rebuild locally. I have also gathered Jaguar/Ford knew these diffs were a weak point and released a service part that was more robust and has also depleted all of its stock. I also was told that if you go to this more robust service part number, more than just the diff will need to be updated. I was wondering if anyone can shed some light on any of these claims?

I am trying to understand the best path forward as I would like to take multiple long distance road trips next summer and would like a quite ride .

Thanks for your help!!

If you really have 25,000 miles I cannot understand rear end issues. These Ford rear differentials seem to hold up.
No LSD is the big issue. Wish they used the Ford 9” rear ends. They are tough and there are plenty of limited slip chucks for them.
Try flushing the fluid. Vacuum out the old and replace with a good synthetic.
But it sounds like a bearing.

I am very certain it is an internal bearing. I don't think changing the fluid will do anything at this point. Jaguar/Ford also did not make service parts for the internals is what I have gathered.

I am told there was a service diff that was more robust.

Generally they are solid and last forever but I gather there was a bad batch / changed supplier or some such - at least for the S-Types. There are posts about this either in the S-Type forum on here or on www.jaguarforum.com and take a look at the TSBs for both.

It's a quite painful set of changes I vaguely recall.

Parts geek and Rock Auto both carry the axle and what I call carrier bearings. Cheap too, these are common parts.
But I would still flush fluid before pulling it apart. Water and other contaminated might effect it. The axle bearing is more common than the differential.

Have you talked to any specialty shops regarding rebuilding one? There used to be shops that only worked on drive line components like differentials and transmissions. I would think someone should be able to locate the bearings someplace. Even if the manufacture does not support them any longer I would not think they used unique bearings. Some things are almost universal in that axle bearings and seals may cross over to something else even if the actual carrier or ring and pinion do not. With such low miles perhaps the fluid was low from the factory. If you do not have any leaks has there been any other incidents that could cause damage. An accident or large pothole where an axle may have been bent?

On the other hand since so many do last 100,000 plus miles a used carrier would not scare me. I would get that before a used transmission and many of those are sold.