Jaguar Repair: My 1985 XJ6 - rear hub issue, rear wheel bearings, axle bearings

Question
QUESTION: Howard,
I believe I may have failing rear hub bearings. On sweeping due-right curves, I begin to hear a knocking, proportional to speed, from my rear left wheel area. I raised the rear of the car tonight and found I can wiggle the wheel ever so slightly by grasping at 12&2 o'clock, 9&3, etc. This produces almost the same sound, just on a smaller scale. With the wheel removed, nothing looks out of sorts, the castle nut is tight with a cotter pin, and it is of course harder to mover the hub, not having the weight and leverage of the tire/wheel assy. in my favor, but it sounds and feels like a shot bearing. Sound like it to you? These are the press-in type, correct?
Thanks,
Michael

ANSWER: Hi Michael,

The rear wheel bearings are tapered roller bearings that are adjusted with a Pre-load and shims in between the inner bearing races. You should not feel any movement on the wheel. But don't forget to check the condition of the axle "U" joints. If you notice there is no upper "A" arm. The axle bearings, axle "U" joints and axle shaft act as the upper "A" arm and support the weight of the rear of the car.

The bearings are sold as a kit with the bearings and seals but you will need to purchase assortment of shims to adjust the pre-load on the bearings.

I found some of the hubs with the bearings very tight and a press would be handy but it can be done with a large threaded rod, spacers and nuts used as a press.

You should get a manual on the car to do a bearing change on the hubs. Then if you run into problems contact me and I will try to help but the whole procedure is too long to write in this program.

Howard

---------- FOLLOW-UP ----------

QUESTION: Howard,
Thanks, Yes, I do realize the rear suspension is unique in not having an upper link, but had honestly not considered the u-joints being at fault here. I guess the whole assembly is going to need to come apart to properly diagnose either as I cannot reliably pinpoint the slack other than what is observed driving, and in the tests mentioned before. I do have a Haynes manual that lists specs for end float and I admit to being a bit apprehensive beginning there as my experience with wheel bearings to this point has been either the tapered fit front style that can easily be serviced with my existing tools, or sealed bearings that are pressed in place and done with no further adjustment considered. I need to decide how to proceed now, so I'll let you know if I need more help. I did read your communication recently with someone else who was having issues with this job, so I'll read back through that as well.
Thanks again,
Michael

Answer
You can do the job with just hand tools and a couple of added home made tools. And to help diagnose the problem jack up the rear wheel at the outer end of the lower "A" frame (which is an "I" beam) That will almost put the wheel lifted up into driving position. Then grab the wheel and wiggle it in all directions. If you feel free play when you "push-pull" at the top that can be either wheel bearings and/or "U" joint. But if you get free play "push-pull" at the front and rear of the tire. That is more likely wheel bearings. You can also remove the wheel and bolt a board or piece of angle iron across two lug bolts and loosen the metal shield over the "U" joint and slide it out of the way so you can look at the joint as you check for free play. It is useful to have someone do the wiggling while you look with a strong light. Don't forget to look at the inner joint and even the inner flange at the differential too as the play can be anywhere along that line.

When I worked at the Jag dealership in FL I had the tools and but now at my home shop I have had to make a few simple home made tools like a piece of threaded rod and some spacers to apply a pre-load to the bearings. and a piece of large aluminum bar stock to drive out the hub when while working on it. I remove the whole aluminum support off of the car and put it up on the bench and held in a vise as I find it easier to work on that way.

You will need to have an assortment of shims to make the pre-load adjustments. Even though I have a few shims, Murphy's law always seems to take effect and I am always short the size shim I need and have to go to the Jag dealer to get them or if you have a few different sizes of shim stock you can make your own as I have also done at times.

Howard