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I found lots of play due to rusted OUTER fulcrum bearings. From looking at the Jag shop manual the play is adjusted by shims between the bearing tubes. Is this correct? I don't know how but some of these shims where all chewed out upon removal. From looking at the exploded view of parts why can't the bearing play be treated like an old school front hub bearing? But instead snug it down till there is no play and use lock tight on the fulcrum shaft?
Replace the bearings and leave the tube and shim in place.
Don't throw away the old bearings and then realize that the thin shim was 'stuck' to the old bearing and now you have to figure out what size it was!!!!!!!
The bearings don't go around & around like normal. They just rock back and forth so the rollers wear grooves in the outer race and that is where the play is.
LnrB sorry I was referring to the lower outer fulcrum.
For some reason there were some badly bend up shims laying in all the grease and then good ones still stuck to the shaft tubes. I removed the shaft tubes to drive out the bearing race.
Although it's not been said yet by 'supercab', I assume "lower fulcrum bearings" means the roller bearings in the rear hub carriers. Whilst most taper roller bearings go round and round as an axle rotates, these ones don't as 'motorcarman' says. The movement of them is not very much at all, only a few degrees as the suspension works, so they wear over this very limited segment and play occurs. Jaguars of this era relied on a number of grease nipples all over the place to keep things like this lubed, and experienced mechanics who understood their importance. So with these mechanics mostly retired or dead, unfortunately they get ignored and the bearings then wear out. It is not helped by Jaguar putting a bleed hole by the grease nipple. The new grease tends not to get to the bearings and mostly passes out this hole. It's best to plug it with a self-tapper and when greasing check for grease exiting by the two bearings, Stop when it starts so as not to damage the grease seal, then replace the screw.
From looking at the exploded view of parts why can't the bearing play be treated like an old school front hub bearing? But instead snug it down till there is no play and use lock tight on the fulcrum shaft?
You might be a trailblazer here
The idea leaves me vaguely uneasy but I'm not able to come up with a reason why you'd be doomed to failure if you tried it. More coffee and mulling needed
From looking at the exploded view of parts why can't the bearing play be treated like an old school front hub bearing? But instead snug it down till there is no play and use lock tight on the fulcrum shaft?
You could use that method but I would use CASTLE NUTS and pins (like a wheel bearing) to keep the shaft/bearings in exactly that pre-load.
Nylock nuts might not hold position reliably????
I remember MGBs used spacer/shims for the front wheel bearings but you could toss the spacer/shims IF you adjusted the bearings properly instead of the 46 Ft/Lb torque.
A voice from the XJS list dares to add:
The rear suspension outer lower fulcrum bearings have to be shimmed to place the bearings under preload. If the shims are missing or twisted up etc, no amount of tightening the end nuts will produce the required preload.
The procedure should be to put in the new bearings, measure the endfloat, disassemble and then put in the required shims to produce the required preload, then reassemble. All of which is not that easy unless the wishbone is off the car and the fulcrum pin can be vertical!
Apologies if I have misunderstood the posting.
Last edited by Greg in France; Feb 7, 2018 at 08:20 AM.
1974 XJ12 question on outer fulcrum bearings
