My 04 xkr was faultless when i bought it late last year, i made a point of having a long test drive and paying attention to the gearbox and gear changes. Gradually over the following months i was getting harsher shifts and a slight knock when stopping, as it was approaching 100k miles i decided to get the gearbox serviced at John SKeggs (indie) in Leicester Uk. The gearbox was much much smoother after the fluid and filter change. The Knocking noise has come back when stopping and i get a harsh downshift and knock when i sometimes stop and try to accelerate.

The garage did not reset the adaptations or update the software, he said he only does this if the gearbox has problems and to see how my gearbox performs after the oil and filter change. Well i now have a problem again and i fear i will have to pay to get the software update. Does what he said make sense or does it sound like he was trying to save a bit of time. I paid over £350 and i dont want to pay even more to get the software update.

The Lurch was not present when i bought the car, so from what i have read it is my driving style that is to blame, why did it not happen for the previous owner, how can i prevent it happening again if i get rid of it.

 

If the correct fluid was used and also if the level was and is correct (note the ifs), just resetting the adaptations should be cheap. If the ifs aren't so then the reset won't fix the problem.

 

Is the software update different from the adaptations reset? I did ask before hand and genuine fluid was to be used. Hence the price.

 

Software update is replacement of the software that runs your transmission controller. It's like a software update on your phone or home computer.

Adaptation reset is a software procedure that runs on a laptop connected to your diagnostic port. The software sends commands to the controller, and instructs the driver to drive for a bit in some narrow band of torque and speed, and exercise each gear. It's a test drive on the open road, if you will, where the car is made to go through some predefined steps. The idea is that the PWM of each solenoid is re-set so it can adapt to the new fluid and wear level of your transmission at that time.

You should expect to pay a diagnostic fee for each procedure, maybe around 1 hr labor.

 

My understanding is that once the adaptations are reset, the car keeps learning/adapting for 100 miles only. After that, it is set to "permanent" values. But the world keeps spinning, and your transmission clutches keep wearing out a bit, and the fluid also looses some of its properties over time. So, the transmission keeps changing, but the software adaptations do not, and these problems develop.

Disclaimer, that is my understanding, I did not code any of this, or work for ZF, or anything like that...

Going forward, check the mechanical part, too. The back of the transmission has a big mount with a rubber insert. The output shaft mates to the driveshaft through a rubber coupling. Also, the halfshafts between the diff and the wheels need to periodically be greased (grease nipple/grease gun type of stuff).

At this point, your best bet is to look into someone that can run that adaptation reset procedure. Try and negotiate something upfront and get someone with experience.

If you look around, there is a lot of procedures for this transmission, fortunately with increasing expenses. You start with fluid/filter. Move on to software. Then you can restore the valve body (solenoids, zip kits, etc). This is all with the trans still on the car...

Best of luck, keep us posted.

 

I believe it learns all the time. The values can also drift, with the earlier software (hopefully not the later).

As posted, just resetting the adaptation (aka adaptions) is simple and not the same as reflashing the entire software (which would be pointless once updated to the latest, though the adaptions are also reset then).

If the internals are worn, then mechanical work would be needed of course.

 

Many thanks for your informative reply it make things a bit easier to understand now.

I have no reason to believe that the indie i went is not up to the job, he does seem to have the knowledge about the Jaguar cars and he has done this gearbox service many times. A few years ago i had a Stype with the same box, at the time the gearbox service was cheaper and the software update was done at the same time. So i was a bit miffed that it was not done on this occasion, maybe the mechanic is right in what he is saying i.e. see how it goes after the fluid change.

So it seems my next step is contact the mechanic and have a chat about getting the software updated. Ill keep you up to date.

 

Many thanks for your reply. Hopefully there is no wear internally. The gearbox was fine when i got the car, ill get the software update and see if that improves the situation. Fingers crossed.

 

I don't know how many miles you have on her, but it might not hurt to look into changing the spark plugs and possibly coil packs. Faulty plugs/coils have been known to throw transmission faults and make the transmission jerky in the x350's, which carries the same drive train as your XK. Misfires can be hard to diagnose and do not always throw fault codes, and short of replacing the plugs, you may never know. They can also cause tapping noises.

Just a thought.

 

I am due to do the plugs etc anyway, oil service was done at indie garage, there is no misfire.