Hey Lads,

For those that have read my previous threads on my transmission, i was looking for a little bit of info.

My car was bumping into first gear as I rolled to a stop.
It was quite the lurch when it would finally drop in and after a transmission service with two loads of fresh ATF and a new filter, the bump is down to just about nothing.

However, it is still there and I want to look into this a little bit further in case there is something that can be done to make it go away for good.

Here is the question I have for anyone running this MY with this transmission:
Does anyone know at what speed the car is supposed to drop into first gear? It seems to me that the downshifting is perfect until I get into second gear. Then the car is only rolling at about 2-3 MPH tops when the tranny finally dumps the car into first.

This seems really late to me and has forced me to adjust my driving style a bit as I tend to now wait for the car to hit that 1st gear before accelerating again. Like you would approaching a red light that turns green before you stop.

My thought process is wondering whether or not this is a programmable thing or if it indicates a failing solenoid or other shifting part within the transmission?

I also seem to remember reading somewhere that the transmission is a "learning" transmission, modifying itself as it learns the drivers habits? If this is true and the car has had such old fluid for maybe a long time, is there a way to more or less "reset" this to start over again?

I have read posts about a computer update or reset that can be performed with a Jaguar software.

 

What AFT did you end up with? There are several options, the more obvious is the ZF LifeGuard 6, the seemingly more popular is the Mercon SP.

My understanding is that after a fluid flush and proper refill to the right level, any subsequent harshness is best addressed with a re-set of the software adaptations. This is a procedure that is applied driving the car through a series of steps while running the Jaguar software.

As for the learning part, I believe it is limited to the first 100 miles after said adaptations are re-set. I do not believe it to be continuous.

 

I used Mercon SP as suggested by the forum.

So I guess my next step in bettering this is to take it to Jag or someone with the appropriate software to reset the adaptations.

 

In the interest of completeness, TSB XJ307-12 addresses problems with the output flange. I suppose there is an off-chance that what remains of the clunk in your car is mechanical in nature, and would not be cured with software. That being said, replacing the flange is more involved than the re-set, so is probably not the first priority. Could probably be tested by repeatedly going from "D" to "R" and check for a clunk.