Curious if anyone is familiar with or has experienced an XJ's transmission slipping into 5th gear with a small jolt or clunk sound? I have noticed it getting worse over the last year. The car is obviously old; but, it only has 75K on it and in great shape. I am hoping the transmission is nothing severe and can just be serviced if possible. I have heard a Jag transmission cannot be rebuilt; is this correct? If it requires a new transmission, I am not sure what to do since it would likely cost more than the value of the car. I just recently put new air shocks on the front too. Also, just purchased a 2015 Mercedes S550 to replace the 04 Jag; so..., what to do with the 04 Jag considering the transmission? I have scheduled the car for a diagnosis at a transmission shop.

 

If it was my car I would renew the fluid/filter and reflash and or 'clear adaptations' to start with.

Then drive to see if there are improvements.

bob

 

Good advice. As the valves on the mechatronic block inside the transmission wear, (very slightly, BTW), the pressures can go out of adjustment and cause the clonk you complain about. A reset of the TCM program and adaptions normally clears it and sets the pressures back to the defined limits. It can get so bad the watch dog in the TCM detects excessive pressure and flags a fault as happened to me.

 

I agree on fluid/filter change with either LG6 or Mercon SP and reset adaptations.

If that doesn't cure your issue more than likely your E Clutch is at the end of its service life.

Rather common issue with 3-4, 4-5 upshift issues. Any codes from the TCM?

 

Thanks to all of you for the replies. I will share all the replies with the transmission shop. Will a standard transmission shop be capable of attending to this or should I bite the bullet and take it to a Jag dealership? Abanano asked whether I have received any fault codes; I have not.

 

Any shop that has experience with ZF transmissions should be able to handle it. A lot of European cars have ZF gearboxes.

 

Hopefully someone who knows what they are doing and who comes recommended should be able to sort it. Another route might be a second hand box. I see them for sale for not too much money, if you could get a known good'un.
Please let us know the outcome
Good Luck

Pete

 

that's a great sign. Go with the fluid/filter change...