Jaguar Repair: My 1985 XJ6, tapered roller bearings, drive axles

Question
QUESTION: Howard,

I'm moving on to the rear suspension this week and have new struts on the way and purchased an air-powered grease gun to lube the fittings as the hand pump grease gun just wasn't cutting it. I have to ask, as I see conflicting info, are the rear hub bearings the sealed type? I'll be checking them once I have the wheels off as I noticed just Friday when I decided to take the Jag to work that on divided highways, with the window cracked and in the lane nearest the concrete divider, I heard a slight scratching sound coming from the rear end. Not the groaning I am used to hearing from a bearing going bad, but more like a light scratching - like if you have ever had a dust plate rubbing a brake rotor - but I don't. I suspect this may be early bearing failure. So, I want to confirm these are sealed-type and cannot perhaps be saved by greasing.

Thanks,
Michael

ANSWER: Hi Michael,

No, the rear hub bearings are not sealed type, they are tapered roller bearings with a large plug in the aluminum housing to grease the bearings. You should jack the rear end up and check for any wheel bearing free play and rotate the wheels one at a time to see if you can hear any noise.

If any wheel bearing is bad you should purchase a service manual as the replacement requires a preload setting with shims available from Jaguar.

It is sometimes better to support the car by the lower suspension swing arm so as to put the "U" joints on the drive axles more in line and under load as they can also make noise that sounds like a wheel bearing. Inspect them closely for any signs of rust as that is a sign they have dried and are bad.

Howard

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

QUESTION: Thanks, Howard

The rear wheel bearing housings were full of grease as I had filled them before, and with the wheels off, I detect no noise at the bearings. I greased all of the fittings on the rear suspension and fitted my new struts tonight, but haven't dropped the car back down on the wheels yet. I am considering having the shop at my work change my rear diff fluid, and thought it might be prudent to provide a new pinion seal when I take it in, but I did not find a listing at local auto parts stores. There is a listing for pinion bearing, both sealed and tapered, roller-type. Do I just need a pinion bearing, does it act as a seal, and then am I looking for sealed or tapered roller?

Thanks again,
Michael

Answer
Michael, the pinion bearing is not a sealed bearing. It is a tapered roller and you must NOT allow them to change the pinion seal unless they are experienced on Jaguar. If you remove the flange nut and flange to remove the pinion seal, you must replace the pinion bearing crush sleeve and reset the pinion pre-load. If they don't know how to do that, it could result in the destruction of the differential.

Howard