Hello, can you tell me if the 1989 XJ40 gearbox is the same as the 1999 XJ8 please. Thank you. Keith.

 

The 3.6 liter XJ6 uses a ZF 4HP22. (in-line 6 cyl)
A 4.0 liter XJ6 uses a ZF 4HP24. (in-line 6 cyl)

A Jaguar XJ8 uses a ZF 5 HP24. (V8) The bell housings will not bolt to either engine as a swap.

No similarity what so ever.

bob