Whine from rear axle, Diff or wheel bearing??
Discussion
It's less distinct on the rear wheels for checking bearings, but listen for the noise getting louder as you go around bends. If you go around a left hand bend and the noise gets worse, it's the right bearing, and vice versa for the left bearing.
The other way to check the bearings is to jack a wheel up, grab it at the top and bottom and give it a good wiggle.
A worn bearing will manifest itself with a distinct movement, and possibly an audible clunk. You can do it with the wheel on the ground but it's not so obvious.
If it's a whine, rather than a rumble, it's probably the diff. However, it wont hurt to check the bearings anyway.
The other way to check the bearings is to jack a wheel up, grab it at the top and bottom and give it a good wiggle.
A worn bearing will manifest itself with a distinct movement, and possibly an audible clunk. You can do it with the wheel on the ground but it's not so obvious.
If it's a whine, rather than a rumble, it's probably the diff. However, it wont hurt to check the bearings anyway.
Wheel bearing failure will cause a rumble or drone increasing or decreasing depending on sideload and introduce some harshness into the ride. You may be able to feel or hear worn bearings at the roadwheel. The XJ rear wheel bearings are not the taper roller type and need a press to remove and refit then. You're probably better off buying a good secondhand hub rather than faffing about replacing the bearings in the one you have. You'll almsot certianly need a 3 legged puller to push the end of the driveshaft out of the hub otherwise it's an easy enough job. You will need to have the rear Camber reset if you fit a different hub
Worn diff bearings can cause the crown and pinion wheels in the diff to mesh incorrectly. This produces the classic whine or hum either on or off load which usually gets louder the longer you drive as the diff oil heats up and thins It's annoying but Jaguar diffs will keep going for tens of thousands of miles like this - they can be quietened down considerably by removing the old oil and refilling with something like a Penrite EP140 which is a much thicker grade then the standard EP90. It's not a fix but a useful cure.
Worn diff bearings can cause the crown and pinion wheels in the diff to mesh incorrectly. This produces the classic whine or hum either on or off load which usually gets louder the longer you drive as the diff oil heats up and thins It's annoying but Jaguar diffs will keep going for tens of thousands of miles like this - they can be quietened down considerably by removing the old oil and refilling with something like a Penrite EP140 which is a much thicker grade then the standard EP90. It's not a fix but a useful cure.
From what I've seen in my own experience the rear hub and bearing set up,at least on the early IRS cars,or even the later type outboard brake type XJS set up,which I'm using on a series 3 saloon,seems to be a weak point in that the bearing sizes and shaft diameter used seem to be too small for the job.
In my case,after some very strange unfathomable handling issues going on at the back,eventually reaching ridiculous levels,it turned out to be that the hub shafts have been running inside the bearings thereby grinding down the shafts,especially the nearside one.
This caused the shafts to eventually end up with massive amounts of play within the hub carriers,thereby causing the centre hub nut to lose torque and then eventually unwind thereby allowing the rear hubs and therefore wheels to move around in ever increasing amounts.It's only a matter of luck at that point that stops the centre hub nut unwinding completely and falling off thereby allowing the hub shaft to come off the driveshaft splines in which case the rear suspension top location goes with it and/or the hub can just come out of the hub carrier first which is what would probably have happened in the case of mine on the nearside,because the hub shaft had been ground down to the point where it was no longer in contact with the bearings and was no longer being supported and held in the hub carrier by them.Only the centre hub nut was holding the whole lot together.
While in the case of the offside the hub shaft was still being held by the bearings but there was obviously still enough movement between the hub shaft and hub carrier for the centre hub nut to lose torque with all the implications of that on the upper suspension location.
All this took place on a re built IRS with recently fitted new bearings.I've now just spent around £600 on a new set of hubs and bearings which I'm about to get fitted.Make no mistake the rear hubs and bearing set up on a Jag IRS,at least up to the late XJS,is a critical safety related assembly and needs to be maintained with no regard to costs whatsoever.If you even suspect that there's problem with it all just throw the whole hub and bearing assemblies out and replace them with new parts all of which are available from Jaguar.I think a similar situation applies in the case of the front wheel bearings and stub axle assembly.Which will probably be the next replacement job on the agenda on the basis that it's probably better to replace all those assemblies on a life expired regardless of seeming condition basis.
In my case,after some very strange unfathomable handling issues going on at the back,eventually reaching ridiculous levels,it turned out to be that the hub shafts have been running inside the bearings thereby grinding down the shafts,especially the nearside one.
This caused the shafts to eventually end up with massive amounts of play within the hub carriers,thereby causing the centre hub nut to lose torque and then eventually unwind thereby allowing the rear hubs and therefore wheels to move around in ever increasing amounts.It's only a matter of luck at that point that stops the centre hub nut unwinding completely and falling off thereby allowing the hub shaft to come off the driveshaft splines in which case the rear suspension top location goes with it and/or the hub can just come out of the hub carrier first which is what would probably have happened in the case of mine on the nearside,because the hub shaft had been ground down to the point where it was no longer in contact with the bearings and was no longer being supported and held in the hub carrier by them.Only the centre hub nut was holding the whole lot together.
While in the case of the offside the hub shaft was still being held by the bearings but there was obviously still enough movement between the hub shaft and hub carrier for the centre hub nut to lose torque with all the implications of that on the upper suspension location.
All this took place on a re built IRS with recently fitted new bearings.I've now just spent around £600 on a new set of hubs and bearings which I'm about to get fitted.Make no mistake the rear hubs and bearing set up on a Jag IRS,at least up to the late XJS,is a critical safety related assembly and needs to be maintained with no regard to costs whatsoever.If you even suspect that there's problem with it all just throw the whole hub and bearing assemblies out and replace them with new parts all of which are available from Jaguar.I think a similar situation applies in the case of the front wheel bearings and stub axle assembly.Which will probably be the next replacement job on the agenda on the basis that it's probably better to replace all those assemblies on a life expired regardless of seeming condition basis.
Edited by XJ Flyer on Saturday 20th July 15:41
Edited by XJ Flyer on Saturday 20th July 15:44
Edited by XJ Flyer on Saturday 20th July 15:49
Edited by XJ Flyer on Saturday 20th July 19:56
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