Its time for a service on my diff and according to my research I have two options.

My car is a 2000 XK8 convertible.

Option one, is getting a 1 inch by 1/2 inch piece of bar stock and using it to remove the fill plug. I assume you use a ratchet wrench to remove the plug, remove the old fluid with a pump and refill.

Option two is cutting a two inch hole in the trunk / boot sheet metal opposite the fill plug for easier access. Again using a pump to drain and fill the diff.

I would sure appreciate anyone who has experience with either method sharing their experience.

 

I have done both. For the 4.2L the bar stock is the only option, but it can be almost impossible to break the plug loose. Before you cut check the link below:

Differential Fill Plug Removal - Jaguar Forums - Jaguar Enthusiasts Forum

 

This is how i did my 99.

Link JagRepair.com - Jaguar Repair Information Resource