Things I learned while doing this service myself in the driveway.

I'll start this off with it is a very doable task for your run of the mill shade tree mechanic.

1. Chalk the front wheels, you don't want her rolling away on you especially while your under it

2. Properly support both sides, I used a set of good craftsman jack stands at the factory lift points.

3. Things you'll need under there with you, a grease gun w/ grease, fluid pump with a 12" hose works well, a little over two quarts of diff lube,( I went with Royal Purple synthetic lube after researching to make sure it met the specs required in the Jag Manual) 1/2 inch drive rachet, 3" extension, drain pan, and a special 1/2 inch 8 point socket(if you don't have one of these or can't find one a 16mm 12 point will get the job done).

4. The fill plug is located about half way up on the right(passenger side) of the differential. Take the 1/2 drive and the extension work it up in there and insert the extension directly into the fill plug and remove. Set this to the side for cleaning.

5. Then you will find the drain plug located in the bottom of the diff in a 2-3 inch circular opening in the sub-frame. You will now need to add the 1/2 inch 8 point or the 12 point 16mm to the 1/2 inch drive extension combo. Position the drain pan under the plug and remove.

6. While the fluid is draining now is a good time to slide out from underneath, and clean the drain and fill plug. On the drain plug since it is magnetic don't be to shocked to find a minor build up of metal shavings, especially if you don't know when the last fluid change was or you know and it was a lot of miles ago. Once those are cleaned up take them and head back underneath. By now it should be done draining.

7. Re-install the drain plug.

8. Take your fluid pump and attach it to your bottle of gear lube. You'll need to snake the hose up to the fill plug opening and insert it making sure that it does not slip out on you, that makes a serious mess on you if your so located. Now just pump your little heart out for both quarts. I found it took about 2.125 quarts of fluid to fill your mileage may vary on that though.

9. Once your done filling snake the fill plug back up there already on the extension I found this made it easier to align and start. Then tighten the plug down.

10. With that done you can now move on to the U-Joints. You'll need the transmission in neutral.

11. There is a outboard u-joint and a inboard on each shaft. With your hand rotate the tire until the zerk is in a good position for you. Attach your grease gun to the zerk and pump away. Once that's complete move on to the next joint and repeat until complete.

12. All done so now it's time to lower the car down to the ground.

13. Make sure at this point to place the transmission back in park.

14. Ready for the test drive now nope not quite go get the wheel chalks out from in front of the tires


Hope this helps someone else be prepared to do their own diff service. Next weekend I should have a complete write up with pics of a headliner removal re-covering and re-install for the xj40 owners as well.

Army.

 

Quick question: Not sure what visc to use. Haynes says 80-90 but that only comes in a 5 gallon by Royla Purple. I am assuming 75-90 is what you used?

 

Thanks for posting, Army. I was a wuss and paid to have the diff done last fall. Like you, the headliner is next on the list. And again I'm wondering... to do it myself or to have it done. That is the question... Maybe your pics will show me the way!

Scott

 

Nice write up Army, have added it to the FAQ. Diff service can often be long overdue.

The only thing I would add, is that when under there, check and lube the handbrake linkages and cable adjuster mechanism.

 

I went ahead and just used Castrols 80w-90 for 5 bucks a bottle. I could not justify the 19 dollar a bottle Royal Purple. My old oil did not look bad but it did seem about a quart low, and there is definatly a little less noise there in the rear now.

Jaguar says every 24000 miles to change the stuff, I don't know any one who has changed it in 100000...

 

Great How-To, looking forward to the headliner one!

 

A substitute for the 8 point 1/2" socket is to use a half inch extension reversed with the female end on the drain plug and turning the extension using a half inch wrench.

 

You make it sound very easy to do. I am hoping to do this before the snow falls this year.

 

thanks for the post.

same here i am looking forward for the complete write up with pics of a headliner removal re-covering and re-install for the xj40.

thanks again bro.

 

"fluid pump with a 12" hose"

Without the above? It will be a long, dirty and frustrating day. In my top ten XJ40 repair/maintenance challenges is this job.

3/8th to 1/2inch adapter is perfect for that nut on the filler port.