Rear Wheel Bearings

[MichaelSB]

Is there any adjustment on the rear wheel bearings of a 1995 4 litre XJS ? I am guessing that it is more specialised and requires shims but I thought I would check here as I have a small amount of play on my car.

[Iain-1980]

The adjustment is via a shim in between th inner races of the bearings.
The bearings are preloaded so if ther is play it is time to replace them.
One thing to note is that play in the driveshaft yokes and differential output shaft bearings is often mistaken for wheel bearings though.

[MichaelSB]

Thanks Iain
I thought as much, I will check again and then leave it to the experts before I do something I regret
Michael

[oldtimer]

Ian,
Please re- check the repair manual. The wheel bearing is not a pre loaded bearing. An end float of 0,002 - 0.004 thou is required. When this is felt at the tyre outer edge , obviously with the wheel in place, the play can feel excessive. Sometimes an MOT tester needs to be advised of this condition. By using a DTI the end float can be accurately measured. Bronze spacer washers with the thickness acid etched on each one are available
As Ian rightly points out wear can occur in other parts of the drive line back to the Diff so it all requires careful inspection

[oldtimer]

PS to the above, I know that David R has recently completed a major overhaul on his rear suspension and he may pick this up and confirm or deny the above

[davidr]

PS to the above, I know that David R has recently completed a major overhaul on his rear suspension and he may pick this up and confirm or deny the above

Indeed. I did but for an earlier car with inboard brakes and so the earlier type of hub carrier.
Assuming that the later type has opposed taper bearings the same then it will need some end float so that it will allow for the bearings tightening up when things warm up.
So I think some play in the bearings when cold is normal but not too much.
However, I've not worked on the later type so they may not work in the same principle. Thankfully, I've not needed to overhaul the suspension in my Celebration yet!
My advice would be to take the car to a specialist who is familiar with these cars for assessment.

[MichaelSB]

Thank you all for your advice, I think this is all outside my skill set so I will let David Marks have Rosie to sort out.
He did a great job on her last time I owned her so that's where I will take her.

[oldtimer]

Hi Ian 1980,
I owe you an apology. I investigated further and found that with the introduction of outboard brakes the hub bearing clearance changed.
For inboard brakes an end float of 0.002 - 0.004 thou is specified
For outboard brakes a pre load of 0.001 - 0.003 thou is specified
Both of the above requirements are achieved by the use of bronze spacers.

For the benefit of those folks not familiar with the term preload.
Using a DTI, Lets us suppose an end float reading of 0.004 thou is recorded, then the hub has to be dismantled to remove the shim in use. This shim needs to be measured with a micrometer and an alternative shim 0.006 thou thinner introduced. When the hub is re assembled and torque loaded to the correct figure then the appropriate pre load will have been achieved. With the road wheel refitted to the vehicle no movement should be felt at the wheel periphery . Sorry, if there is start all over again ! I hope that makes sense.

I'm intrigued why after so many years this change is introduced. I would have thought that if the outboard brakes cause a rise in hub temperature issue the bearing clearance would be increased not decreased. Who knows