Hi,
I have seen a 2000 XJ8. Gorgeous, most dealer stamps. All rust work done, however, the gearbox is confusing.

It is aggressive on the downshifts, according to the seller.
If it was supposedly serviced regularly, it makes me believe the transmission fluid isn't the issue. It is concerning as the car is sitting on 78k.
My XJ8 would do this but it needed a transmission fluid top up..this was at 178k.

What do you think?

 

You could need a new valve body as described by Gary here....
He describes the main issues with this trans, the final one sounds like what you describe.


But, you may be able to get ahead of it before it breaks and replace the pressure regulator valve with this kit...ZF5HP24 Valve Body Pressure Regulator Valve Repair Kit.

https://www.ebay.com/itm/12199764772...sAAOSwjDZYkig~ ...thing is I'm not sure how available this is in Europe?

 

This is very important to do on any XJ or XK that hasn’t had it already… on mine, when the pressure valve went, it blew out both the a drum and the valve body. It ended up needing a full transmission rebuild, around $4,000.

I remember that it went out while downshifting as well.