Gen 2 only have the drain plug , I don't remember if it's the 3/8 or 1/2 square drive to get the plug out either way you'll see when you're under there .
I swapped my diff out a few years ago now I end up going with a shorter final drive ratio from a gen 2 LS Lincoln / thunderbird

 

Was it a bolt on swap or it required some modification? Stock XK's drive shafts were ok?

P.S. I will try with the oil change first. Will see if that will help. I will probably go with this: Valvoline SynPower 75W-140 Full Synthetic Gear Oil


It says it has additive for LSD. Hope that wont be an issue since my XK has an open diff.

 

It will be fine.

Richard

 

And I guess going full synthetic gear oil, like above, is acceptable. Any additives to avoid?

 

GL5 synthetic is the recommended oil. The only additive which you are likely to come across is the LSD additive. It won't do any harm but gear oil with the additive is usually more expensive than oil without so you might as well buy the cheaper stuff.

Richard

 

I have had to replace the diffs in my last 2 cars, an X150 and X358. Bought used diffs on ebay. The one for X358 is fine. The one for the X150, not so sure. Has a whine, too. The fill port takes a 3/8 square drive. There is no drain port. 1.25l and I used 75w140 Amsoil Severe Gear lube, no additives. They are open diffs. May have the original X150 diff professionally rebuilt as a backup. Don't really look forward to replacing another diff on a Quickjack Portable lift. Great lift, but lying on your back to R&R a diff isn't fun at 70.
The failure on the X358 was the left side carrier bearing. On the X150 it was the pinion bearing. Parts for the TSB are NLA - diffs, drives, axles. The only options are rebuild or take a chance on used.

 

Now that I'm thinking about it, could I swap in an LSD diff from an XKR of the same year? If I'm going to replace the diff anyway, might as well upgrade, right?

 

Both the xk and xkr use the same diff , also throw in the xf , & xj which also run an open diff although the xj uses a 2.89.1 final drive

 

Steve is correct. The LSD diffs didn't come til 2010 and they won't fit, parts not available. If you will get the numbers off the diff housing, you can usually find a match on ebay. I'm looking at one there now. But, that's a risk.
The best thing is to have yours professionally rebuilt. Bearing kits are available. There are instructions on here about how to do it. https://www.jaguarforums.com/forum/x...lation-155867/
Bearing and seal kits. Timken p/n DRK311, DRK311B, DRK 311BMK https://www.ebay.com/itm/374468311147
If you are mechanically inclined, it's a simple if not easy job. Even a small scissor lift like the QuickJack portable is a great help. And a short transmission jack. The hardest part is accessing the 2 retaining bolts in the frame and
then torquing them. Had to have friends make a flat piece of 3/8" steel with a cut down socket on one end and 3/8 drive on the other for a torque wrench extension, then do the math to re-torque.
And absolutely paint mark all three of the driveshaft bolts. One of them has a small balance nut on it and they all must go back where they came from.
Let us know what you decide.

 

How do you delete a post? Like this?