For the next time someone throws out the "sealed for life" tripe ...

XJ/K 'diff oil change - PistonHeads

 

So what fluid do you use since you can't get the Shell Spirax Super TS90?

 

When I rebuilt the GKN Salisbury open diff in our '93, I couldn't find the specified Shell Spirax Super 90, so after some research I used Lucas 75W-90 full sythetic. It works fine with no problems. If you have a Limited Slip Diff, you'd want to do your homework to be sure the Lucas is suitable. With some of Lucas' gear oils, they claim no friction modifier additive is required in LSDs, but I'd be tempted to use an additive anyway.




Cheers,

Don

 

Another little known observation about the use of synthetic lubricant in
differentials.

Synthetic lubricants are believed to run cooler than conventional.

BUT, and this is a huge but ...

that is the lubricant itself. The parts that the lubricant is supposed
to draw heat from actually run hotter than with conventional.

The source is Currie Enterprises who are well known as axle builders
for aftermarket and race applications. They built an instrumented
axle then ran it under test conditions.

I speculate that the synthetic runs cooler because by transferring
less heat energy away from components it does not get heated as
much.

The temperature limit for differential lubricant is pretty much 300* F.

These temperatures can be reached on the track in twenty minutes.

Corvettes do poorly because of their IRS which have no axle tubes to
contain more lube or radiate more heat. They also run the exhaust close
by. Sounds and awful lot like a Jaguar IRS. US market Corvettes do not
get differential coolers. EU market Corvettes get them standard. Makes
you go hmmm... they must expect that extended runs on the autobahn
are going to be enough to cook the differential.

When and if the extra diff and lsd go into my XJR, it will sport both
conventional lubricant and a cooler. Or at least be tapped for a
cooler and temperature gauge.

The vendor of the lsd specifies conventional and will void
warranties for synthetic.

Oh yeah, and safety wired bolts. The temperatures reached in
a hot differential are enough to break loose red loctite.

++

 

Original message:
Good day,
I'm looking for a replacement for shell spirax super ts90 75W90 Gear Oil for my 1999 Jaguar XJR ‏. Thank you.
-Erick

Reply:
Hi Erick
The diff needs a SAE90 LSD oil, like the Fuchs Titan Race Gear 90LS, Castrol Axle Z or Motul 90PA.
http://www.opieoils.co.uk/c-679-sae-90-gear-oils.aspx
Regards
Tim

Is this information accurate?

 

The little that is known suggests that Shell Spirax Super TS90
is a straight SAE 90 GL5 with LSD additive. Notice that there
is no mention of 75 in the name. The TS stands for "thermally stable".

As a matter of fact, it is listed as a straight 90 on the bottom of
the linked page.

 

So I'm having most of the Jags fluids drained and refilled Monday and the one thing I'm stuck on is the Differential Fluid/Gear Oil. I'd like to buy the recommended version and avoid settling for a GL-5 Synthetic 75W90, but now I'm up against time. Ideally, I would have gotten the Fuchs Titan Race Gear 90LS, but I can't receive the product by my required date. I'm going to have to pick up something local.

Does anyone know of a good US substitute?

FYI, I've thus far decided on the following fluids for my other systems:

Transmission Fluid: Febi Bilstein A/Trans Fluid P/N 0019892103
NAPA AUTO PARTS

Brake Fluid: Pentosin Super Dot 4
NAPA AUTO PARTS

Power Steering: Any Conventional Dextron III (open to suggestions) Do I need to replace my PS filter?

Coolant: Peak Gold "Lifetime"

Motor Oil: Mobil 1 Synthetic 5W30 Extended Performance

Differential Oil: Unknown

 

I popped in the BMW Dealer today (Jag was closed ) and found they had Castrol SAF-XO. Expensive, but I'm popping it in the Jag Monday!

So that's solved!


YAY!