XJ-12 Rear Hubs / Wheel Bearing Lubrication
 

On reassembly of the IRS on my '88 Vanden Plas, I was unable to turn the drive shaft without the aid of a pry bar on the wheel studs. (The IRS is still off the car). This was noted after connecting the driver side half shaft. I removed the small cap on the hub casing and added a bit of oil, and after some soak time, I was able to rotate the shafts by hand, with no pry bar. To me, this suggests a pending problem with the wheel bearings in the one hub. Thoughts/comments?
Also, I checked the service manual and I do not see any suggested lube for these bearings, so would I be correct to conclude that the bearings are packed on assembly, with grease, and that's it i.e. no requirement to add grease, or oil, as part of the maintenance schedule? Given the access cap, it would seem easy to add oil from time to time, although I am not sure the oil would actually stay within the hub. Likely grease is the intended lube, but there is no way to get the grease into the bearings without complete hub disassembly and repacking with grease.
As always, all feedback will be appreciated!
Thank you,
Wayne

A long time bugaboo. IMHO only the generous size of the bearings saves us from seeing more failures than we already do

The same wheel bearing grease you use on your front bearings is fine but, as you say, getting the grease *into* the bearings is another matter. The usual thing is to remove the cap, fill the hub with grease and hope some of it actually gets into the bearings.

On my XJS I installed zerk fittings into the little caps so I could leave the caps in place and pump grease under a bit of pressure...hopefully increasing the odds of it getting into the bearings.

I've thought of mixing up a slurry of gear oil and grease, giving a slightly liquid quality to the grease, in hopes of keeping the bearings lubed.

Notice how often the word 'hope' is being used ? :)

Others will chime in.

Cheers
DD

I was going to say something incredulous but I don't think I need to.

Next time Nix is jacked up things will happen back there!

I'm thinking a cheap flowable grease and just pack it in. With no brake discs to heat it up to evaporating point, it "should" work.

Or not?
(';')

I did Dougs modification years ago to ALL the hubs on all 8 of my Jags.

I used standard wheel bearing grease, and thats it.

As for "grease flow", I reckon it will.

Grant's scientific test.

When you come home from a short drive, feel that hub, it will be very WARM towards HOT, and I reckon warm enough to give "some flow" to that grease.

Never had issues with those bearings, and with Sir Arthur now at 560000kms, I doubt he ever will.

Thank you Doug, LnrB, and Grant for your feedback. You responses have confirmed my concerns re lubrication on these wheel bearings. Hopefully, mine are OK for this season anyway, as I have to get that IRS re-installed soon and I do not want to take on any new jobs right now.
FYI, there were "semi-fluid" greases on the market years ago; they were designed for leaky industrial gear boxes, and I believe they could be suitable for these bearings. Not sure if they are still available, but I will do a bit of research on a rainy day. For now, I am going with the addition of oil to the hubs, which will give me that "slurry" lube. I will just have to check from time to time to make sure it does not all run out, in service.
Thanks again for the feedback and suggestions!

Penrite still make a semi fluid grease used for trailer bearing hubs and good for about 130C.....never tried it but might be worth a shot.