Hello I have problem and I'm not sure what's wrong with the car I need to have an idea before I take the car to the mechanic . There's clunking sound in the rear end only when fully turning the car I believe it's only the right side
no noise when driving straight or even over bumps
rear shocks are billstein 1 year old changed with the donuts
Im not sure what's the cause of this sound
​​​​​​could it be wheel bearing Or something else?
​​​

 

Look at the rubber hangers for the exhaust pipe.

 

Hangers first as the exhaust can be shifting to the outside , you may see some marks on the tire , there is a rearmost hanger at the rear bumper , quite a challenge on it's hardware as the pipes hook into the rubber

In my opinion 2nd check and cheapest , the wheel bearings and depending on the taper of the wheel bearing for which side

 

I can't see what model you have but the XJR and, I believe, some other variants have a rear anti-roll bar. I had the same symptoms as you and it turned out to be that the bar was loose on one side owing to the mounting not being torqued up.

 

The exhaust hang in it's place i think I the rear end need rebuild as I saw many bushings in very bad condition
Whats good brand for the wheel bearings and how many bearing need to be changed since I will rebuild the rear end ? I honestly prefer aftermarket as the OEM very expensive or maybe not even available . Thanks

 

To map out your parts and their names

Search Genuine Steering And Suspension Parts For Jaguar Xj 1998 - 2003 (from 812317 To F59525) (x308) Classic | Jaguar Land Rover Classic Parts

and a bushing source

Jaguar XJ8, XJR, XJ Sport - X308 (1997-2003)1994 to 2002) Replacement Suspension Bushings (powerflexusa.com)

The bushings come in different densities and roll bar thickness bushing depending on your model , supercharged

How To Choose | PowerflexUSA

You can pour your own from a 2 part mix on the internet and some have done this

There are threads on the X300 and X308 section as they are very much the same

 

It turned to be the bushings and right side wheel bearing
Which means rebuilding the rear end $$$$$