XKR rear differential failing
 

Hello all. Help needed here!
I have a 2004 XKR convertible which I bought 15 months ago from a specialized dealer.
He did a full service including replacing all fluids (also rear differential).
There was a leak visible on the differential before service and he dismissed it as no big deal.
Now after a year - and out of his warranty :-( the differential is making a very loud noise that is growing louder.
It sounds similar to a failed wheel bearing. A grinding sound that grows louder as the car goes faster.
There is no change in the noise when I apply power or let it roll on neutral.
it took the car to another garage thinking it was a simple wheel bearing issue. They called back saying it wasn't and are looking at what needs to be replaced.

Can you help me further investigate and are there any known subsystems (bearings etc) that need to be replaced as opposed to the full differential?
Any advice or similar story most appreciated

Thank you
Antoine

If they have eliminated wheel bearings as the source of the noise, you will have to work inwards towards the differential. It could be an axle shaft UJ or differential output shaft bearing. Speed related makes me think UJ as prime suspect.

https://cimg4.ibsrv.net/gimg/www.jag...b0f65d4d32.jpg


Another possibility is failed A Frame bush (sse item 5). This allows metal to metal contact with a lot of transmitted noise.

Graham

Thank you very much. We're looking!