Hello, My Jaguar has about 150k on the clock, now when reverse is engaged there's a "clunk" as the car moves back!
Any suggestions would be appreciated, David

 

Well, a few things come to mind.

1) Rubber drive coupling on the pinion flange of the diff is past its use by date.
2) If NO rubber coupling, the 4 bolts that hold the pinion flange TO the prop shaft flange are loose. Seen that many times.
3) Idle is too high, and the system is "winding up" too fast.
4) Halfshaft uni joints need a good greasing. Probably not been done since 1994. If they are too bad, new uni joints will be needed.
5) Transmission mounting needs attention.

A quicky repost in the XJ40 section will get you many more suggestions, I am sure.

 

David,

I've moved your question from General Tech Help to XJ40 forum. This is the place to post tech questions about your model.

Graham

 

Thanks, I think you've covered it all.