Differential oil change.

[BillDag]

Jaguar XJR 350. 2004
As my car up will be in the air I'd like to carry out a differential or change.
My car is fitted with a differential with no drain plug. (I guess it is one of Jaguars sealed for life components!? ).
So how to drain and I guess I have two options.
To pump/siphon out the old all by the filler/level plug?
Or to remove the rear differential cover then at least be able to clean it all out.
But where to get a new gasket.
Last but not least how much and what sort of oil to put back in.
Thanks again.
Bill Dag.

[J44EAG]

Bill,

You should see a square 3/8" drive plug on the back of the diff. You will need an oil sucker pump. Oil refil level is when the oil begins to dribble out of the plug hole. Saw all this done when my car was on the ramp at Tom Lenthalls works.

Oil is 75E140NT and you will need around 1.5 litres. You will need to pump or syring the new oil into the case. Pay special attention to any oil leak from the NS drive shaft. Repeated need for a new oil seal on that side indicates the need for a diff exchange or rebuild. Tom found that if the centre of the diff has worn, then NS oil leaks give an indication of an issue.

This link gives an indication of oil change procedure. The car must be level when top up is done. https://www.google.co.uk/url?sa=t&rct=j ... 3KoYz5iD2Q

The oil that was removed from my car was a rancid grey colour at 80k miles. Jaguar recommend a change at 90k. In my opinion, a change would be better carried out every 40k miles in an attempt to keep diff lubrication at a better level.

Mike

[oldtimer]

Bill,
I changed the diff oil last year on a routine service at about 46/48 K miles and equally as black and rancid as Mike K says. I bought a syringe especially for the job but discovered it was too large , I ended up with oil up my arms over my shoes, every wear , what a bloody mess. The trouble was when the suck hose was pulled out of the diff the oil in it ran everywhere.
So, obtain a fairly small syringe but a length of rubber tube will be needed in order to get to the bottom of the internals - Make sure nothing can drop inside or you'll be in trouble. Good luck with that !

I have an advert for a 9 litre oil extractor, hand operated or compressed air line which might well do the job easily but at £80. 00 I'm not sure

[BillDag]

Thanks for your replies.
Sounds like changing the oil is a must given the state of the oil in your vehicles.
I am tempted to remove the differential cover so I can give it a good clean out.
Is there a reason not to do this.
Regards.
Bill Dag.

[J44EAG]

A double or triple oil change will be more beneficial, Bill.

If you remove the diff cover all you will see is the crown wheel and pinion. It is such a small diff that you will be unlikely to get in there to do much. Cover removal is rather overkill in my opinion.

Mike

[oldtimer]

Like Mike says , don't bother , change the oil again next year.

[BillDag]

Thanks for the advice.
Another look at the differential and yes you're right Mike the rear cover is used to support the differential. So it would be a lot of work to remove.
So I will go the pump out route.
Regards.
Bill Dag.

[J44EAG]

I spoke to Tom Lenthall about diff failure issues last week.

Failure of the near side drive shaft seal gives an indication that something is wrong. Tom says upon stripping a suspect diff, he often finds the centre portions of the crown wheel and pinion to be failing. Rebuild or a new unit is then required. Tom finds it cheaper and more effective to then replace all the internal parts with the Quaife LSD unit. Issues are not just confined to X350 but also to S-type and XF. Costs for the Quaife unit rebuild are around £1800 plus VAT.

Failure of some of these diff units has been put down to poor cleaning procedure at the factory after case machining when originally built. Evidence of machining swarf has been found. In addition, it is thought that some diff units may not have had cleaning fluid totally removed at build stage. This would obviously affect the lubrication quality of the 75W140 oil in service. The situation is not encouraging.

Only the other day I had a member phone me about a 350R diff problem. 46k mile old X350R with a near side drive shaft leak. The local main dealer changed the diff and prop for new. The cost was nearly £3k.

Mike