On Replacing the Output Shaft Oil Seal

Diagnosis. You will probably first notice a new stain on the garage floor from the area of the differential (also called final drive). When you investigate more closely you might discover that the leak seems to be coming from between the brake disk and differential. If you have not caught it early, you may see the pads and disk coated with oil and you might even smell sulfur when you get out after a drive. The sulfur smell is they hypoid oil being heated on the hot brake disk.

Before you start. If you're not experienced and are only a fair mechanic, like me, this is a tough job. Labor at the dealer$hip is about 5 to 7 hours and it took me about twice that amount. Parts are fairly cheap (about $30 for the seal and $10 for the O Ring). It is messy and hard to reach and hard to deal with when you reach it. You will need a torque wrench (good in the 45-70 foot pound range) and a 1 7/8 inch box end wrench or equivalent. I also recommend a loooong pair of needle-nosed pliers and needle-nosed vice grips. You also need safety wire. I used 18 gauge mechanics wire from NAPA (I think that it said annealed) but any malleable steel wire is probably OK. Don't get the really stiff stuff. Last, be careful and give yourself time. Several steps are very frustrating.

To provide some perspective. I paid to have this job done at the dealer$hip shortly after I purchased my car. That required driving to the city 100 miles away, paying about $500, and renting a car overnight because of a dealership screw up. Also the $500 was reduced from the first price of $700 after much negotiation and based on the estimated time I had been given. But, even with all that, I am not yet convinced that I did the right thing by trying it myself this time. On the plus side, I now know about the rear braking and suspension systems. Anyway, ask me in a month. If the problem reoccurs or if the caliper leaks because of a stupid thing I did late one night, then I'll wish I had done differently. As it is, the car had better behave for a while.

It has now been about 6 months and the repair has stood the test of use. No leaks, no problems. Yes, I would do it again. This time I would drop the subframe. I didn't drop the subframe because I saw that the Jaguar mechanic did not when he made the first repair. I thought that what was good enough for him was good enough for me. Now, I think differently. However, you don't have to drop the frame and should not be intimidated by the lack of space and access. It's tight but, in the right frame of mind, it is OK.

If I had to choose one thing that I most wished that I had known before starting it would be this. The collapsible spacer is a little metal tube that would be very hard to compress and does not have to be replaced anyway. Based on my reading, I thought it was some fairly soft material that you had to be very careful not to over compress. If you want to replace it or need to replace the bearings, my personal recommendation would be to mail or take the stub axle to a mechanic for this one step. Shouldn't cost but about $75 in labor. My description is based on reusing the old bearings and compression spacer.

1. Thoroughly clean the underside area where you will be working. You won't get it all, all but it is a very messy job at best. The combination of grease, gear oil and brake dust is very nasty.
2. Support car on stands placed before the jacking points & remove road wheels.
3. Take off hub carrier grease fitting to protect it from damage.
4. Remove nuts from lower shock absorber mounting and drive out threaded rod. I drove out from rear. The nuts are 11/16. If only doing one side, then you can use undisturbed side as a guide on reassemble. If not, take notes.
5. Remove safety wire from radius rod bolt, remove bolt, and remove. I had to break the radius rod free by driving the wedge-shaped end of a pry bar against the top of the bushing. It was tough to get loose. Safety wire goes through bolt and is made immobile by being wrapped around strap. The radius bolt is 5/8 and the safety strap bolt is self-threading 9/16. It has a washer.
6. Slide back the shroud to expose drive shaft to disk bolts. Lift the hub carrier with jack to get at the 4 11/16 nuts, remove nuts. I used ´ inch ratchet with 2 inch extension. Remove the bolts and let drive axle down gently. It is heavy. Note the number of shims between drive axle and rotor -- I had three. Access to one nut is made more difficult because of grease fitting.
7. Remove support plate retaining bolts.
8. Notice that I did not drive out the fulcrum bolt as is described in Haynes.
9. Remove pins and take out brake disk pads. This step couldn't be easier. Just pull out safety clip then slide out pin. Nice to see something done well and made easy on a Jag.
10. Remove hand brake cable from parking brake/caliper arm. Mine was right side so was easier. Just work end of cable free and disconnect spring.
11. Drive down tab washer tabs and take out the two parking brake assembly bolts using a 3/8 socket.
12. Remove safety wire and two bolts holding the caliper in position and disconnect brake line. Brake line should be plugged. This was tough. I had to use a 5/8 offset box-end wrench to reach bolts and it took for ever. I also couldn't find a good plug so fluid was dripping on me during the process.
13. Take parking brake and brake caliper apart and slide them out.
14. Take disk rotor off and note the number of shims between it and the caliper mounting flange. Mine had two. It isn't hard to tell these shims from the others as these had curved sides to fit the recess on the brake disk rotor.
15. Cut safety wire and remove 5 bolts holding caliper mounting flange to final drive. Note that you rotate the stub axle to allow access to the 5 bolts. I used a ´ wrench with a 2 inch extension.
16. Pop caliper mounting flange loose and withdraw. I rotated it so that the x was at the top before removing. By this point, I had put in about 6 hours work.
17. Renew oil seal. Mark the face of the nut at the right edge of the key way so that you can put everything back exactly as it was before. I also used a combination square to measure distance from end of shaft as a double-check. Flatten tab washer then remove nut. To remove the nut from the shaft, I had to buy a 1 7/8 inch box end wrench ($28). I said that as if it were easy to do. Mine was not. It required much force to remove. The caliper mounting flange had to be placed in a shop vice and much force applied with the wrench. The wrench I bought is about 2 feet long, no kidding, and it wasn't easy. Once the nut is removed, slide off the tab washer. To remove the inner bearing I had to strike down on a wood block with the shaft while holding only the caliper mounting flange. This caused the bearing to come out, followed by the compression spacer. The shaft then came out. The outer side of the caliper mounting flange shows a metal cap over the oil seal and the outer bearing is visible underneath. To remove the cap and seal, I had to use a drift to drive the seal out from inside out. It is now all apart. Replace the O ring and pack the bearings and lubricate surfaces with petroleum jelly. Replace the outer bearing, push the new seal into position, place the cap over the seal and drive into position using a board and hammer to spread the force equally. Put bearings back in same position. If you replace bearings then replace both sets. Insert shaft. Work compression spacer into position. This takes patience. When the spacer is past the beginning of the threads you can use the nut to force down. Then slide the outer bearing on and drive down gently and evenly. Slide tab washer back into position and replace nut. I tightened the nut back to the original position using the combination square to identify when I was getting close and the scratch mark as a final guide. You will not pass the mark without notice. It gets very difficult to tighten the nut. Hint: if you don't have an adequate vice then use the brake rotor to hold the bolts in position and clamp down the rotor using rubber-faced clamps. Randy Wilson's response to my question about the compression tube was as follows. If your are simply replacing the seal, and reusing the old bearings, then don't bother with the new crush tubes. Mark exactly where the retaining nut is, and put it all back together to the exact same spot, using all the old parts. If the preload is off dramatically (it will be a tad looser than spec) it is due to bearing wear and the bearings should be replaced. If you induce new bearing preload in a set of old worn bearings, they will fail shortly thereafter. When replacing the bearings, I do things as above, with one notable addition. The end result I'm looking for is just "this" much past the point of zero clearance, call it about 10-20 degrees more on the nut. Since bearings tend to be very close in tolerances, you can often reuse the old crush tube. I mark everything as before, then use a dial indicator to check on exactly when the bearings hit zero clearance (end-float) as I tighten the nut. The nut has to be getting tight at this point, when the nut does align with the marks, it will be very tight. If all of this does not happen, then it comes apart and a new crush tube is used. These crush tubes take a considerable amount of force to crush. It is difficult to hold the flange in place in a vise, and turn the nut. The torque required is so high that something wants to slip. This is the reason I avoid using new ones when possible. When I do have to use new ones, I do most of the crushing ... down to about 0.10" bearing clearance, with a press. Rather than using the nut to push the inner bearing down to crush the collar, I have a mandrel I made up to push it with a 30 ton pneumatic press.
18. Replace the stub axle assembly and tighten bolts to 60-69lbs. Notice that you should screw in each bolt nearly all the way so you can rotate the axle to expose the next bolt hole. If you just put them in loosely at first you will find the rotor bolt heads hitting the caliper mounting flange bolt heads and it's a hassle to correct. Now comes safety wiring. It was my first time. It would be smart to practice in a comfortable area. Not me. It would also have been smart to have carefully noted how the wiring was done before removal. Not me. Instead, I wired the 12 o'clock, 10 o'clock and 7 o'clock bolts together on one wire and the 2 o'clock and 5 o'clock bolts on another. That was mainly because of the relief around 6 o'clock but was probably unnecessary. I did the wire through, twist, wire through next, twist etc. method. It looks good and might even work. My only hints are to (1) use vise grip needle nosed pliers, (2) make the wire run perpendicular to the bolt path on the first bolt (or the wire will try to slide on top of the bolt), (3) remember that the twist will exert rotational force on the wire so when you are doing a bolt in series, the bypass wire should run to the right if you are twisting clockwise. I had to try each wire twice and it took well over an hour. Maybe it will be better next time.
19. Replace disk rotor. Slide parking brake calipers up and in approximate position then insert brake caliper. I made a mistake here that cost a lot of time. I did not read the directions regarding parking brakes and didn't realize the problem until I had struggled for far too long. I thought that I would just put it back like it was. Not so easy. The parking brake has a self-adjuster and I must have caused it to reduce the distance between pads while I was trying to line up the bolts. It is better to spread them before assembly, put the bolts in, then ratchet the parking brake until it doesn't ratchet any more. I also had trouble getting the tongs to hit the holes, but I had trouble with everything. Anyway, reconnect the brake line and put the two caliper bolts back. Tighten the caliper bolts and wire them. Apply moderate force to the parking brake cable to hold the parking disks in position and approximate position and tighten the parking brake bolts. Bend up tab to hold parking brake bolts in position. Note that it is easier to attach the hydraulic line with the caliper free. Replace pads.
20. Replace outer shims and raise hub to point that you can reattach drive shaft. Replace nuts and torque (49-55 lbs.).
21. With hub raised, reattach radius arm bolt, safety strap and safety strap bolt. Torque and safety wire radius arm bolt (40-45 lbs.). Jag-lovers consensus was to smear the radius arm mating surfaces with anti-seize to make future disassembly easier.
22. Lower hub and replace lower shock absorber bolt with spacers and washer correctly located (35 lbs.).
23. Bleed brake caliper and thoroughly clean disk and pads with spray cleaner. Don't get this stuff in your eyes. It burns like Hell until you flush it out. Wear goggles.
24. Check differential oil level and replace connecting plate.