Gilly, yes the XJR's (supercharged) from 98 on use the 722.650. I think the XJ8's use the ZF trans. In fact that is part of the problem because there are relatively few XJR's when compared to XJ8's so there aren't too many Jag people who are all that familiar with them. The Jag dealers are told to simply replace any bad 722 (not rebuild).

I need to verify but I think the tech said code 731-incorrect ratio. I'll verify today.