I rebuilt the front end of my 92 XJSC. All new rubber. The hub has new bearings, races and grease seals . Brakes have new rotors. No work on the calipers or brake pads.
I managed to seat the grease seals using a length of PVC pipe that allowed be to hammer only on the inner part not the rubber. Looks like it seated properly. The races look like they seat as far as they can go in the hub.
When I installed the hub on the passenger stub axle, I tightened the the nut to about 15lbs and then spun the hub and backed off until there was minimal drag. The picture shows the very minimal clearance between the caliper and the outer surface of the rotor. The clearance between the rotor and outer and inner part of the caliper is not equal at all. The outer is only about 1/32".
When I did the driver's side, I could not stop the outer boss of the caliper from binding the rotor. There is maybe less than 1/32" if I tighten the bearing to 15lbs but that is far too much drag.
OBVIOUSLY, I have done something wrong on both sides. I am thinking the rotor should be centered in the caliper.
Possible causes:
Wrong inner grease seal keeping hub from seating as far inboard as it needs to. I compared it with the original and they look the same.
Wrong inner inner or outer bearing race keeping hub from seating as far inboard as it needs to. They look right, but that's really difficult to tell. Same with the bearings.
Pictures. One is the passenger side showing minimal clearance. The other 3 are the driver's side showing no clearance and the rotor location in the caliper.
I am desperate for suggestions, even those that highlight my stupidity.

Passenger side showing minimal clearance

Driver's side showing caliper boss on rotor

 

I think you must have the wrong bearing in the inner, or that the inner bearing outer race is not seated properly. It is clear that the hub is not being allowed to go far enough inwards, only the bearing can account for this. Check the seating and if needed Buy the correct bearing set from a known Jaguar specialist. The grease seal cannot account for this problem. It is the depth of the inner bearing that controls the hub position.
I have also been told that later cars hub/spindle assembly might be different, in that the grease seal might have to be loaded onto the spindle, rather than fitted to the hub first. A search might turn something up.

 

I think this is the same as this thread By Jerry, with the answer by Baxtor at #5.

Good luck.

https://www.jaguarforums.com/forum/x...-seals-244693/

 

Please excuse me if I am mistaken; but I think you have mounted the discs on the wrong side of the car. Thde slots should slope rearwards, froom the centre to the disc rim, when the wheel is turning forwards. It looks to me like they are sloping the wrong way - remedied by swapping the discs over lhs to rhs and vice versa.

 

I want to thank those who have given some thought to my problem. If I were cleverer and more observant I think I might have arrived at what I now believe will be the correct answer. The information and picture that I did not think relevant before would have shown that the castellated nut and cotter pin actually line up with the hole in the stub axle. This means that the hub and bearings are probably seating where they should. Moving it inward might help the caliper problem, but then the cotter pin would not align with the hole in the stub axle when the bearings are properly adjusted. Nevertheless, the caliper is binding the rotor by at least 1/4". Since the caliper mounting bosses are fixed and the caliper cannot be shimmed, by the process of elimination, the answer must be that I was sold the wrong rotors. Although they bolt into the hub, are the proper diameter and look perfect, they do not bring the rotor surface where it should be in relation to the caliper. I am going to remove the calipers, hub and rotor and compare the height of the new rotors to the old. I am fairly confident I will see about 1/4" difference in height.
BTW, the rotors were marked left and right. I assume that we determine that from the driver's seat but it appears this vendor marked them from the front looking rearward. If the seller is willing and can supply the proper rotor I will install them as Jerry suggests.

 

wufibugs,

As Greg has said, the discs are installed on the wrong sides. I can't comment on what might be causing the problem. However, no-one refers to car components as Left & Right when looking from the front of the car. Based on that alone, I would be hesitant about buying any replacement parts from that supplier.

Good luck

Paul

 

Thanks to both Greg, whose name I botched, and Paul for pointing that out.

 

The depth of the rotor hub should be 35 mm. Measured from the outside face of the bell to the outside face of the disc.

 

Greg, that is so very useful and I thank you. Went out and did a quick measurement and the new rotors look to be very close to 35mm. I also measured the old rotor and it is the same. As it now appears that the rotor is not the culprit, I am back to square one in my search for what I screwed up to make the caliper bind the rotor even though the hub lines up with the axle stub hole for the cotter pin.
Measuring at rear of the caliper where the brake pads slide in, you wouldn't happen to know the clearance between rotor and body the caliper is? This would tell me just how much I am off, though I'm still baffled as to what I could possibly change to recover the missing millimeters.

 

Now that I think of it, if the pads are to wear evenly, the rotor would have to be centered in the caliper. To get the proper distance at the back of the caliper, I measured the width of the opening, subtracted the width of he rotor, then divided by 2. I got 65mm - 24mm -: 2 = 20.5mm. The drivers side that binds at the hub side of the caliper is uneven. AT the back it measures 17.5 and 23.5 between caliper and rotor. The passenger side is about 1mm from being even. Does not bind, but the rotor and the caliper at the hub side is very very close.

 

wufibugs,

I'm interested in your statement that 15lbft causes too much drag. See the attached article from the knowledgeable Bernard Embden and see if that helps at all:

Jaguar XJ-S Front Hub Rebuild (bernardembden.com)

Cheers

Paul

 

I fabricated a heavy 5/8" fender washer that fit the stub axle but would push on the hub not the bearings and tightened down on the axle nut to seat the hub. It did put everything where it should be. I will have to drive the car a few blocks for the caliper pistons to calm and see if my heavy handed approach damaged any of the bearings.

 

I did read that article. At this point I'm going to have to take a very short drive to seat things and then I will try Bernard's method. Right now, things are not turning very freely which may be a function of how many times I've had the hub off and on. If things don't free up a little, I'll have to take the hub off and see if I've trashed the new bearings.

 

I strongly caution you against road-testing these obviously not correctly mounted brake/rotor assemblies. What will you do at even 15 mph if they fail? So I think you would be far better advised to pull off the hub and start from scratch.

1. remove the calipers
2. remove the hub from the stub axle
3. make sure the outer race of the inner bearing is COMPLETELY seated into the hub. This is in my view the most likely cause of your problem.
4. once you are dead sure that all is 100% correct and the bearing outers are absolutely driven down to the stops in the hubs, carefully reassemble, ensuring the inner race of the inner bearing get right up to the stop on the stub axle.
5. without the calipers mounted ensure the hub/bearing/stub assembly is right, that everything turns freely, and is properly adjusted.
6. then offer up the calipers and see what is what. This is not a mystery problem, it is just a matter of carefully ensuring each step is correct.

 

What Greg said for sure.

I agree with the Cup not being seated in the hub correctly.

As you have stated, you have possibly screwed those bearings, so start again is my strong advice.