XJS rear wheel resistance

There should be very little resistance to rotation, provided you are not trying to overcome the resistance of the limited slip diff.

The easy way to check is jack up the car so both wheels are free (I usually put a stout block under the diff plate). Release the handbrake, GEARSHIFT IN NEUTRAL, and turn one wheel. What you should see is the other wheel turning in the SAME direction, it should be fairly free to turn and the prop shaft will rotate also.

If you put the car in park (or in gear) then the diff input is locked and the wheel should now be very stiff to turn (near enough impossible by hand), this is because of the pre-load on the clutch pack inside the diff. If you do manage to turn it (ie using a bar) then the other wheel will turn in the opposite direction.

I have a 1989 xjs v12 recently i suspected i had a rear wheel bearing going. i took the car to a garage the mechanic jacked the car up and checked for play on the wheel his conclusion was that it was not a bearing fault but he suspected my rear brakes were binding. The car was put on a rolling road which identified that it has 30 pound of resistence on both rear wheels. The noise i suspected was a wheel bearing turned out to be a disk cover that had come loose. The car now drives perfect with no noise however i am concerned about this 30 pound of resistance on the rear wheels.Does anybody know what the resistance should be on the rear wheels considering diff, drive shaft etc