As long as this thread has gone on as long as it has, I didn't mean to highjack it. Just wanted to thank those that have contributed with good advice.
My XKR does not have shifting problems or any other physical symptoms...other than a little chirp when shifting under load from 2nd to 3rd gear. I am assuming that a little fresh fluid will silence it. It's as simple as that.

 

Regarding the ZF 6HP26 Adaptation Drive Cycle re-set procedure performed by a Jaguar dealership, my wife's 2006 XK8 has had it done twice. Once in July 2013 at 68,000 miles due to her complaining about rough upshifts, and again in April 2016 at 101,500 miles due to her complaining about the same thing. The dealership indeed did not want to perform it a second time and initially talked me out of it claiming that it may lead to premature wear-and-tear on the solenoids. But a long phone conversation with ZF tech support in Chicago convinced me that at 101,000 miles we had little to lose by having the procedure performed again. So I phoned the Greensboro dealership service manager, explained that I had ZF tech support's blessing, made the appointment for the procedure, and had it done a couple of days later. Once again, it restored my wife's XK8's ZF operation to normal. No idea how long it will last this time but it was $150 well-spent since I haven't heard a peep out of her since....

By the way, we also did a ZF drain-and-fill using Mercon SP in early April, and we'll do it again in October just for good measure. Without dropping the pan, expect to get about 4.5 quarts out of it....

 

Following up on jon89's post, there appear to be two issues being discussed, although I am not sure whether both issues (chirp AND rough shifts) were experienced by his wife. I have no issue with rough shifts (at about 60,000 miles), so if the reset procedure is intended to cure that, I wouldn't need to have it done.. So can we clarify: did the change of tranny fluid to Mercon SP cure the transmission chirp problem?

 

I have a 03. Trans felt like it was going back and forth between 5th and 6th when cold and if I didn't come to a complete stop it would bang into 1st as I applied the go peddle. It has 116.000 miles so I thought it was time for fluid change as I could find no history of it being done. Dealer wanted $1200 that wasn't happening. Found an independent ,Oxford Motors, in East Providence RI that gave me a quote of almost $700. I pulled the trigger after a month or so. They changed the filter and fluid and found the loose connection that's been giving me fits. $597.00 I was very happy with the price but the trans still acts the same when cold🙄

 

Atlastajag1,

Yes, the initial Mercon SP drain-and-fill cured the ZF squawk. The dealer-performed Adaptations Drive Cycle procedure cured the rough shifting. We're doing another Mercon SP drain-and-fill in October to ensure that at least 85% of the ATF in the ZF 6HP26 is indeed Mercon SP....

 

Is getting these "adaptations" reset something that only a dealer can perform?

 

Some indie shops have told me they can do the adaptations drive cycle procedure with their AutoLogic systems. However, if you ask enough questions, the honest ones will probably admit that they have never actually done the procedure before. While I prefer to avoid dealerships as much as possible, this is one exception I make because I trust the experience and integrity of the two longtime Jaguar master techs at our dealership in Greensboro (about 80 miles away from us)....

The ZF 6HP26 "Adaptations Drive Cycle - IDS Procedure" is Technical Service Bulletin JTB00145 dated February 3, 2009. Be aware that some Jaguar dealerships no longer have the equipment, software, or experienced techs available to perform this service, so be sure to do your due diligence before you schedule it....