Hi, I have had my Jag a week now, and love this car. However so far I have only driven shorter trips.

Yesterday, I took my car out on the highway (Norwegian standard) for a bit longer distance, and it seems the gearbox couldn't decide what gear to cruise in. Not that it shifted all the time, but like the gearbox considered it.

This affected the ride for me, as the car wasn't as smooth as I wanted it to be.

Do you believe an oil change with filter should do the trick? If so, should I empty the converter too?

My car is rather old 96/97, but has only 41500 miles on it.

 

Have a look in the 'HOW TO' thread under Transmission Issues - ’96 - '02 XK8 ZF 5HP24 ( https://www.jaguarforums.com/forum/x...ts-data-29800/ ) for discussions and advice on fluid changes in the so-called 'sealed for life' transmissions.

Graham

 

Mine tends to shift between 4th and 5th when cruising at 60 to 70 KPH in standard mode, especially if there are hills. Use sport mode and it should stay in 4th most of the time. If you still have a problem the fluid may be low.

 

I have the same issue in my 6HP26 box, but only during the first 10 minutes of travel. When the transmission gets warm, everything works fine. I changed the filter/pan and oil last summer, but the "cattle grid effect" remains when cold.

It is probably due to solenoids wearing out. Replacing those require an overhaul of the transmission mechatronic, which is probably out of my league DIY-wise.

Other car, same gearbox, same problem:

Parts:
Mechatronic Parts: The CTSC - ZF Parts