At slow speed ( idle ) with the windows up I can hear a clicking noise, I have checked the universal on the driveshaft and the output shafts of the rear end. Does anyone else think it could be a bad bearing?
Thanks

 

Cricket in the trunk?

 

Need to be a little more specific, check your rear tyres to see if you have picked up a stone in the tread or gotten a nail/screw in one.
Or it maybe a cricket! LOL.

 

The Cricket is dead so that's not the issue. The tires are new and had them changed after first noticing the noise. I have jacked the car up and put it on jack stands, spun the wheels by hand and heard nothing but when I put it down and back it out of the garage the clicking is back. I have even gone so far as to mark the tires and cheked to see if the noise occurs in the same place in relationship to the tires and it does not, making me think bearing.

 

It is possible the click is from the driveshaft splines at the outer hub. At very slow speeds one can get a clicking noise especially when on a bumpy surface. I have heard it myself on my old XJ6. Jaguar actually Loctited the splines to stop it, thus forcing use of a puller when removing the hub and hub carrier. I think there was something about this in the XJ Series 3 workshop manual. Of course the XJS has the same rear suspension.

 

I would check what Fraser has proposed firstly, I don't have enough experience experience with these cars to comment otherwise. If you don't have any success there look over your suspension pieces, springs, shocks see if any are cracked or loose and failing. even worn rubbers on the suspension components can cause weird clicks or creeks. Bearings squeal when failing and normally disintagrate soon after, same with diffs and much of the other parts under high turning stress.
Good luck

 

Does the frequency of the clicking sound change at all with a speed change, or is it constant regardless of speed?

Do you hear it in reverse?

Thanks,

John
1987 XJ-S V12
63,000 miles

 

My money is on the handbrake mechanism somehow hitting the disk.

Greg