My 2014 XJR only has 42K miles and I wanted to service the rear diff.
It's a simple job with a bit of tricky access to the fill plug.



Used a 5/16" Ball Hex but I think it's really a 8mm Allen on the fill plug. I used a short arm Allen wrench to break it loose then my 5/16" Allen socket and ratchet to spin it out.
The same short arm wrench fit the transmission fill plug on my old S Type R. Luckily this plug is not nearly as tight as those darn ZF transmission fill plugs!

The drain plug is a 3/8" square drive. The plug was surprising easy to turn. I put it back with much more torque.




Old oil looked pretty bad and had some real viscous stuff in the pan. I have read about carbon shedding and carbon in the clutch plates. So really black may be normal?
Factory says use Castrol SAF Carbon Mod fluid. I found Redline 75W90 #57904 meets the spec. I have always liked Redline.




Nice magnetic drain plug with some very fine powder on it. Nothing much at all.




Another odd thing is Jaguar wants 2.5 Pts in the rear diff so you don't fill until it overflows the fill port. Can't see why and after the change it was very close to over flowing anyway.
Car feels and drives fine but I had no problems before either. With the look of the factory oil I plan another change in 10K miles or so.
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I just did this 2 weeks ago on my 2012 XJL 5.0 SC with 125k on it. Mine was very dark, more so than yours even. The worst part was cutting down my 8mm to have clearance to remove the fill bolt. I also used Redline 75W90 and for anyone going with Quarts that's 1.25. MIne did not overflow at all. I did let mine drain for 6 hrs starting with warm fluid. My magnet was caked with metal shavings. So far so good with the new lube. In fact I think my rear was switching to one wheel wonder sooner before new lube. Now it can put more power to both wheels under hard acceleration and turning.

Car is new to me so I did a trans flush and filter as well with Redline D6 as well.
Good write up with nice pics!

 

I was hoping someone would post about how the car feels afterward?
Mine seems to put the power down more evenly and I "think" I see less traction control light blinking on hard launches?
Not sure but it has a slightly different feel.
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Mine was changed at the dealer @98k and noticed a small difference in the the diff locking a little faster. However, I never get the traction control light on launches as I am running larger Michelin PS4S tires and they have awesome grip.

 

I have MPS4s as well. Amazing tire. You can nail it and just take off.
To anyone that hasn't done this service around 100k I think its worth it. Your talking less than $30. DIY

 

I run Michelin Pilot Sport 295's on the rear. But I have around 620 HP compared to stock so I can break the tires loose almost anywhere at any speed.
Going 60 mph on dry pavement if I mash the throttle I get a few flashes of the traction control.

Maybe a 305 or 315 tire would help?
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I should mention I also run 295/35R20 rear tires. And I have stock HP.

 

Thread Revival

I'm looking to change my diff fluid again as its been nearly 4 years and 50k miles since the last (first) time I did it. I used Royal Purple 75w90 at the time and I see Club used Redline here. Are there are any new and improved fluids that I haven't heard of?

 

My 2011 XJL now has about 22K on it, with about 8K of that in the last 12 months since I got it.

I don't remember seeing this done in the 10 years of service history.

So I guess the question I have is should I plan to change this sooner due to the age of the original lubricant ? Or am I good for another 30-40K ?

 

Its pretty cheap and easy to do, so I would go for it considering the age.

 

I don't think the 2011 NA engine had the E-Diff?
Pretty sure you have an open rear diff? Still good to change the oil but not as critical if you had the E-Diff.
Also will take a different fluid.
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