I suspect from your post that you are not planning on tearing into the transmission yourself, so I would recommend you try and find a competent transmisison repair facility that represents that they work on ZF gearboxes. There is a known defect in the XJ8 transmission that does not require complete overhaul to repair, but it is still a major operation and requires removal of the tranny from the car. Once you have done that, most shups would recommend a complete overhaul, I suspect.

 

Dont drive the car anymore!!! If you haven't driven it too much while it has been acting up, you might be able to get away with repairing a part in the transmission called a 'drum'. Maybe a $1,500 job at a mechanic? It's a lot cheaper if you do it yourself. The more you drive it, the more the transmission becomes damaged which could lead to metal fragments floating around the trans fluid. You would then need a trans rebuild. That is much more expensive than $2,000. Thousands more.

 

Hello and welcome to this Jaguar forum.

Here is a PDF file "XJ8 Summary at a Glance" that has some of the Major Repairs issues including the ZF5HP24 transmission issues:
https://www.jaguarforums.com/forum/a...lance-test-pdf

First page of the file is a Menu page with list of Engine, and Transmission Issues listed along with menu button that take you to the details of each issue.

The ZF5HP24 transmission has three listed issues: Fractured Forward Drum, Valve Body Damage, Transmission Control Module (that might need to be replaced).
The menu buttons for these transmission issues takes you to another page in the PDF that summary information and menus items to other posts and articles about the issue (such as the forward drum summary information and menu items such DIY forum posts about the forward drum repair).

Also you can find even more forum threads about the transmission by going to the XJ8 & XJR webpage:
Jaguar XJ8 & Jaguar XJR - Jaguar Forums - Jaguar Enthusiasts Forum

Forum - Jaguar XJ8 & Jaguar XJR 1998-2003
Header line -Threads in Forum : Jaguar XJ8 & Jaguar XJR
End of Header line has Search this Forum then "down arrow"

Click on the "down arrow" to open the search box
Put in the search term ZF5HP24 (this will bring up a list of 25 of the most recent forum posts on your transmission model issues on the first page and another 29 on the second page.

Jim Lombardi

 

Just out of curiosity have you ever changed the transmission fluid?