Daimler differential leaks, front brakes and fuel tank

May 1, 2026

My Daimler was off the road for some years before I acquired it. While cars that haven’t seen a lot of use can have advantages in terms of wear and tear on the interior and body, lack of use is often worse than regular light use for mechanical components.

One of the things that became apparent in starting to use the car regularly, was that the differential had a fairly major leak. This is obviously bad for the longevity of the limited slip diff, but on the XJ series cars, the rear brakes are inboard so major leaks can impact the rear brakes.

The independent rear suspension used on the XJ and Daimler derivatives is the same independent rear suspension unit introduced on the E-Type in 1961. It was still far ahead of everyone else when the X was introduced in 1968, and continued to be throughout the 70s and early 80s. It was only when the competition introduced multi-link rear suspension systems in the mid 80s was it surpassed. The original version was used until the end of XJ Series 3 production, and evolutions of the system were used until the mid 2000s.

The reason the independent rear suspension for the XJ is related to the differential is the design of system has the entire rear suspension, differential and brakes in a removable rear subframe. Therefore to fix my differential leak, the rear suspension had to come out of the car.

On my car the exhaust system wasn’t in great condition and had to be cut before the rear suspension could come down. This will need to be replaced later. The good news is that the underside of the car is in good condition. With the rear suspension removed, the differential could then be serviced. A clunk in the rear suspension was traced to be due to bent trailing arm mount brackets.

While the car was in having the differential leak fixed, a few other things needed sorting out, including:

Leak from transmission pan gasket
A couple of small coolant leaks from coolant hoses
The fan clutch was not engaging properly when the engine was hot

In addition to those things, when changing a fuel sender on the left hand tank, it was clear that the cleaning the tank a few months ago hadn’t worked very well. The tank was still very dirty. New fuel tanks are still available, so I was able to purchase one and have it sent directly to the workshop to be fitted. I had feedback it looked like it was very good quality and had some kind of internal ceramic coating.

The front brakes were leaking and so the calipers removed to be rebuilt. In doing so, it was clear that it was necessary as the pistons were in pretty rough shape.

I also had some new external rear view mirrors fitted, including one on the passengers side. This wasn’t optioned when the car was new, but I park very close to a wall in my storage area and I don’t want to damage the side of the car.