Well done, Roger.
A very necessary job on all modern Jaguars. I recall Jaguar schedule this service work every 90K miles. My own car was treated to a diff oil change at eleven years of age and some 80K miles covered. Here is what Tom Lenthall removed from my car. As you found, rather smelly and nasty and definately with little lubrication quality still remaining.
Seeing the appaling quality of my oil at such a low mileage leads me to suggest that it could and probably should be changed at much lower mileage intervals. If I keep this car for a long period of time, which is something that is likely, then I shall be replacing that oil after another 40k miles of use. The cost of the oil is peanuts when compared with the cost of having to have a diff rebuilt. A new Jaguar supplied diff is known to have cost one of our members £2800 recently. Obviously regular replacement of oil will help towards avoidance of that outlay. A stitch in time can save nine.
Tom Lenthall often finds his business having to change worn out diffs on XK8, S-type, X350 and XF models of varied years. Tom is one of only three businesses authorised to supply and fit the Quaife LSD units. As I understand it, the cost of him rebuilding a diff with that LSD unit is around £1800. Cheaper than fitting a Jaguar replacement unit by £1000 and able to give an improved level of traction control. The unit is completely mechanical and works well with the traction control system fitted to the car. In fact it cuts down on the amount of DSC activation/interferance by the electronic module. I`ve seen one of these units in action in wet conditions when fitted to one of our Regional members S-type. Most impressive it was too.
I can only but recommend low mileage diff oil changing to owners of modern Jaguar cars. There was apparently an issue with some brand new diff units where it is alleged that the diff cases were not properly cleaned of machining swarf and that cutting fluid also remained in the caseing. Obviously any contamination of this type does little to help longevity. Indeed the member with the £2800 unit mentioned above, had diff failure at just 46K miles. Whether contamination was a contributory factor is unlikely ever to be known. But we know there can be those issues and that fact alone should encourage all of us and particuarly those with lower mileage cars (under 90K miles covered) that have never had a diff oil change done, to get it actioned as a matter of urgency.
Tom tells me that an early sign of diff issues is the failure of the near side drive shaft oil seal. If a replacement seal is fitted and that also fails, then it is time to consider replacing the complete diff or having Tom, Viezu or Racing Green Cars fit the Quaife LSD alternative option.
Oil service maintenance is vital for a modern Jaguar regardless of what model you own. This is applicable also to supercharger and gearbox oil and filters. Ideally, those two oils should be changed at each and every service interval. Personally, I disagree that diff oil can be left until a 90K service aniversary. 40K or 50K intervals appear a better idea. That diff oil is subject to extreems of heat and pressure not to mention oxidisation. Nothing lasts for ever and that includes all oils used in our cars. Filled or sealed for life recommendations should be ignored. That is just not possible.
WIth luck, as Roger suggests, hopefully his 186k mile car has received several vital oil changes in the hands of East Riding Council. Roger and I drove each others cars recently. Despite the high mileage of Roger`s car, it is certainly a good example of the model and there was no diff noise detectable. One hopes that Roger`s car did most of its former work as a long distance cruiser rather that being used for many short journeys. Long distance work is what Uncle Rob calls "good miles" and which keep damaging use to the minimum.
Glad you got that done, Roger. That`s another job off the list.
Mike
