I have a 2004 s type and the when I start driving the transmission does not shift smoothly. After the initial shifting it then seems to shift alright until I stop or slow way down and then it does it again.

 

take a look at Jaguar S-Type Ownership Experience - The ZF LURCH Fault, you are not alone! Your trans is a ZF 6hp26, it seems to have a few issues. My own car often lurches in to first gear, it has had a fluid and filter change but it is no better. Some people report an improvement by having the software updated - often called a reflash - to the latest version. I will be getting my car done as soon as I can arrange it. Originally KJaguar said these transmissions were sealed for life but now they say the fluid should be changed at about 60k.
hoope that helps.

 

Yes. The Lurch lays it out in fine detail.
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