Rear diff oil

[DougX]

What is the recommended mileage/years for changing the diff oil? Has it got a drain plug? 2005 X100

[M100TWO]

Model and year would be helpful.


John

[mike020150]

There is no Jaguar recommended change period for the differential oil (sealed for life). As a result, there hasn't been a drain plug on most Jaguar diffs for a long time. To change the oil without disturbing the diff's internals, it's necessary to syringe/vacuum it out. Mike.

[DougX]

Thanks Mike. Only question now is, the gearbox on my X-Type was indicated as sealed for life, but in reality this needs to be changed certainly within 10 years or 100k miles or less as I am told the the oil degrades over time. So what mileage/time period is suggested to change it? Will it be the same as the X-Type gearbox?

[mike020150]

Hi Doug,
Luckily, diffs impose less stress on their oils than engines and gearboxes because the oil stays cleaner for longer. It's never a bad thing to change the oil but there really isn't enough information (hard evidence) to give a firm recommendation on mileage. Assuming they are not abused, most Jaguar diffs seem capable of over 100K miles on the original oils. However, particularly if there is evidence of wear (noise), an oil change can help reduce the rate of wear. Mike.

[DougX]

Hi Mike, great advice. My XK8 has only undertaken 77k and no noises, so I have to assume it’s not necessary to change the oil.

[chisron350]

Hi Doug,

A diff or gearbox failure will be more than expensive... better piece of mind... change the oil. Get it done by an accredited garage.

Good luck, Ron C

[ptjs1]

Doug,

I would take a very different view and definitely change the oil if its done 77k.

Diff oil is under extremely strong shear forces and the smell and colour of used diff oil is indicative of the toil that it's subjected to. And without the benefit of a magnetic drain plug, it's also more difficult to remove the minute metal wear particles that build up in the XK diff, so even more reason to change it frequently.

I change my diff oil in all my cars every 30k (and my transmission oil much more frequently than that). Excessive? Who knows, but oil is cheap, and engines, transmissions and diffs are expensive. My x350 had had 6 transmission oil changes when I sold it at 155,000 miles and I noticed it's now racked up over 200k, so maybe I got something right.

Even without a diff drain plug, it's pretty easy to change the diff oil on your car. As Mike says, just syringe out as much as you can. Then do it again at 100k. 30 mins of your time and an absolute false economy not to do it.

Why are the transmissions and diffs marketed as "sealed for life"? It's a really simple issue and completely misleading. In the US, in the 90s, vehicles were starting to being subjected to being compared on a "cost of ownership" basis. That was a figure calculated for the planned maintenance costs over 3 years or 60k miles. So Jaguar liaised with Esso to find a way of not needing a transmission oil change for 60k miles so that cost could be eliminated from their cost profile. So Esso developed a longlife gearbox oil that was deemed to last for at least 60k miles. The first cars they were fitted to were the XK8 and the x308 saloon. And Jaguar then advertised the gearbox as "sealed for life". So even if some failed at less than 60k miles, they were replaced under warranty, but it was still worth it to Jaguar, as long as they didn't have to have a service schedule with a gearbox oil change in 3 years. So, Yes, they are "sealed for life", it's just that their life is sometimes much shorter than you might think! Even Jaguar later changed their policy and recommended a fluid change at 60k. And the diff is the same. It might do 100k on the original oil, but why would you gamble for the sake of £40 worth of oil?

Seriously, change the diff oil now. The car will thank you for it.

Good luck

Paul

[Lucky]

Seriously, change the diff oil now. The car will thank you for it.

+1

[DougX]

Thanks everyone for your comments. I have decided to have a major service next year when its annual service is due and will get the gearbox oil changed and the diff oil at the same time. May even go the whole hog and have the spark plugs changed as well, as I have arranged a number of European driving trips.