XJ8 DIFFERENTIAL 1998 3.2 SPORT

[SEASPANNER]

Hi there,
got an increasing vibration from back end,feel it through the seat,wheels balanced and swapped about,no change.Got her up on a ramp today for a look and found all u.j.'s to be ok but when rocking car back and forth there is a heavy clunking from pinion area of diff,all drive train looks great and sounds great when driving,just this "clunk" when putting on power after overrun and the vibration.
Don't suppose it could be the input flange nut on the pinion backing off???? Being very optimistic here.Failing that has anyone got a diff they can ship to me here in Italy??
Appreciate any input as usual...cheers.

[Jaguar steve]

I'm guessing here, but if the diff was that shagged to clunk and cause vibration I'd expect some noise too. Possibly whining either at certain speeds or on acceleration or deceleration.

Did your check include play in the prop centre bearing - shuddering vibration at certain speeds through the body is a clue here - , or the prop UJ's. What about rear wheel bearings? Diff oil level?

If it turns out you need a replacement Eurojag could probrably supply a good second hand one.

[Jaguarnut]

I'm not sure of the suspension set-up of the V8 XJ's, but a common source of rear end clonks on XJ40's and X300's are either the shock absorber bottom mounting bush or the large bushes (2 off) that locate the rear "A" frame, just in front of the rear wheels. If the same arrangement exists, these items may well be worth investigating. They are replaceable at home - just - with a very good toolkit, jacks, stands etc and access to a workshop with an engineers vice or a press. I've done it but it certainly tested one's expressive vocabulary!

[SEASPANNER]

Thanks for the comments lads,am going to have to take her to the local jag garage here in italy as i have no where to do the work or even the tools or time to do it.At least now i have a few more ideas and things to look for once we get her up in the air again.thanks again for the input,will keep you posted.

[SEASPANNER]

Can't believe it!! Took her to a jag dealer here in Italy,went for a test run to verify vibration,then up on wheels free ramp and put her in gear,tyres look a bit "humpy" so probably that.
Anyway......i nip round the car to check the wheel bearings for any play and the front o/s wheel is clunking when i try it.......turns out that the top ball joint nut was just about off.......they fitted two new front bearings about 3 months ago and i haven't done many miles since......so after a quick rattle with the zip gun and locking wheel nut tool wrecking session I was out of there,no charge,no slowing down and no going back!!!! Our lives in their hands eh?????? Hardly felt a thing through the steering either. Old girl will need to return to UK for some therapy later.Just have to drive above 110mph to kill the vibration.