I had a clunky /whiney box in my 04 xk8, after changing oil and filter to no avail I took it to Swallows Jaguar near Weston Supermare .I had the gearbox software updated via a laptop, it cost about £35 and made it as new . Money very well spent .
Just in case anybody is stuck with a clunk and thinks they need a new box.

I now have an xkr with merc 5 speed, I don't know if it has its own ECU, does anybody know .

 

It does, but is a while different animal from the ZF 6 speed. If it comes time to service the transmission and you want to firm up the shifts a bit, you can search for "blue top solenoids".

 

ccrulton, In the Thread above you mentioned "Blue Top solenoids" is this in reference to the ZF 6 Spd. or the Mercedes 5 spd? My ZF doesn't seem to know where it is or what it is suppose to do Half the time.....Also, where do I find more info on the Program Re-Flash?

Billy Clyde in Houston

 

I found this http://www.mercedesmedic.com/reset-m...-instructions/

Does seem to help.

 

Thanks, ill read the fix after work. The zf fix is a software update,done in about 20 minutes. I had it done at an independant dealer,twas excellent.

 

The blue top solenoids are for the merc 5spd, there is no such "shift kit" for the ZF and it all comes down to software and how the OEM wanted the transmission to behave.

The software update requires someone that has the dealer SDD software to do it. But it is never a sporting feel, it seems Jaguar wanted it to always shift too early and too slowly.

 

Billy Clyde,

The ZF 6HP26 shift qualities can be improved by having the ZF Adaptation Drive Cycle procedure performed by a competent dealer. The TSB (Technical Service Bulletin) describing this procedure is JTB00145. Check your chosen dealer's experience in performing this procedure before you agree to let them perform it for you. If they have never done it before (and are honest enough to tell you so), I would keep looking for an experienced dealer before committing to it. I would also recommend doing a proper ATF drain-and-fill BEFORE doing the TSB procedure. When my wife began complaining of rough shifts in her 2006 XK8 in July 2013 at 67,000 miles, Rick (joycesjag) and I did an ATF drain-and-fill and then I had the TSB procedure performed. That cured the rough shifts until she began complaining about the same issue in April 2016 at 101,000 miles. So Rick, Wayne (cjd777), and I did another ATF drain-and-fill and then I had the TSB procedure performed again. That was more than a year ago, the car is now approaching 110,000 miles, and my wife has not complained of rough shifts since then. Rick, Wayne, and I did one more ATF drain-and-fill in November 2016 at 106,000 miles just for good measure....

I negotiated a $150 price for the TSB procedure with my chosen dealership's service manager, and he assigned his lead master tech (more than 35 years of Jaguar service experience) to the job both times. My wife couldn't be happier and I think his price to me was very fair. The process takes 1.5 to 2 hours depending upon the traffic conditions at the time (the clearings and resettings are performed while the car is being driven) and the skill of the techs. As I recall, you live in Houston. So I recommend that you contact Brutal and have him perform the procedure for you....

I run Mercon SP ATF in both of our ZF 6HP26 units (my 2005 S-Type and her 2006 XK8). It meets the required Shell M1375.4 specs and can be purchased at any Ford dealership for $6 to $7 per quart. I highly recommend Mercon SP to any ZF 6HP26 owner with a transmission that is now beyond its warranty period....

 

Jon89, Thank you so much for this informative answer...I have changed the ZF's oil twice now and both times were with Mercon SP as I noticed the Lincoln Navigator has this same Tranny and Ford recommends Mercon for it..

It's not the Oil but it is something screwy...It wants to stay in 2nd and then after a bit, it hammers into 3rd just makes it worst in "S".....

Billy Clyde in Houston

 

If you have fresh Mercon SP and you are confident that your fluid level is indeed correct, then go ahead and spring for the Adaptations Drive Cycle procedure....

 

Has anyone ever heard of a dealership refusing to flash a transmission? I took my barn-find 2005 XK8 with a hard 1st-to-2nd gear shift issue to a Land Rover/Jaguar dealer in Las Vegas, after first having a transmission service done by a trusted AAMCO shop (helped but didn't cure). The dealer flashed everything except the transmission, which they claimed was giving a error code for a 3rd-to-4th gear issue (never felt it...), saying that they could not clear it and were afraid that they might do the transmission more harm. They would not tell me the specific code and gave me a very ambiguous invoice, but they "highly recommended" that I immediately change out the transmission, which they would be happy to do for only $8,600 (plus tax). (They also said that my lightly-fogged right headlight (just after a hard rain) would require a new replacement for $760 plus install.)

 

[QUOTE=Jon89;1678559]If you have fresh Mercon SP and you are confident that your fluid level is indeed correct, then go ahead and spring for the Adaptations Drive Cycle procedure....[/QUOTE

Jon89,

Hey Jon! Who is "Brutal" and where do I find him here in Houston.....Sounds like someone I need to know! You would think that a great Jaguar Mechanic would let the secret out, unless he is already snowed under......

Billy Clyde In Houston

 

I think there is a fear that resetting the adaptations on a 6hp26 over 100K will cause damage as it will slip more than normal while it learns the adaptations- hooey in my opinion, but nevertheless a real fear.

 

Yeah, I got a similar fearful story from the dealer.

After a while, when I had my own copy of SDD, I flashed it and did the adaptation drive cycle. Shifted rather abruptly at first, but it still drove ok. After doing the cycle it smoothed out and no more problems, and I did it at 80k miles.

Only issue that is left is the torque converter clutch, which I know is a physical problem and have just been nursing along for a few years now.

 

That's his name on the site - you can contact him via PM I expect.

You can easily Search and read his posts.

 

Billy Clyde,

"Brutal" is a highly-respected master Jaguar tech in the Houston area who occasionally chimes in here on the forums to answer our questions. He stays extremely busy and does not post here nearly as much as he did a number of years ago. I believe his real name is Bill Bruton and I assume that he still works for one of the major Jaguar dealerships in the Houston area. As JagV8 suggested above, you can search his posts and attempt to PM him. You could also call the Houston dealerships and find out where he works. Pay very close attention to ANY advice he happens to give you....

 

Regarding dealerships refusing to perform the Adaptations Drive Cycle on our aging ZF units, my trusted Greensboro dealership initially recommended against performing another procedure on my wife's XK8's ZF in April 2016 at 101,000 miles after having performed the first one in July 2013 at 67,000 miles. Their reasoning was that it may greatly increase internal clutch wear and therefore do more harm than good. But keep in mind that dealerships are NOT transmission specialists - they much prefer to just swap transmission units rather than attempt to repair them. So I called ZF tech support in Chicago to discuss the pros and cons of doing another procedure at this stage of the car's life. They were not nearly as concerned with resetting the adaptations to factory specs as my Jaguar dealership was and suggested that for my negotiated $150 price, it was well worth trying before a last resort of tearing into the transmission for a rebuild. So I called my Jaguar dealership service manager again, told him I had obtained full clearance from ZF tech support to go ahead with the procedure again, and promised him that I would assume all risk for whatever consequences resulted. That was good enough for him. I brought the car to him the next day, the procedure was performed again, and I have not heard a single peep out of my wife regarding rough shifts since then. Indeed, money well spent....

 

For anyone interested in speaking with ZF tech support in Chicago, you can reach them at (800) 451-2595. Ask for Steve Jaffe or Joe Laubinger. Both of those guys have taken extensive time out of their days to educate me on the 6HP26 on multiple occasions and I truly appreciate their kind assistance over the years....

 

Can you elaborate on this a bit? What makes you think there is something wrong with it? Any codes? Thanks for sharing.

 

There is a shudder and mild surging when the converter clutch tries to lock up while the transmissions is cold. It is a known problem with the early 6HP26 and ZF later redesigned the seal in the converter clutch. If it gets really bad it will throw a code, but mine hasn't yet.

In my case, it doesn't do it when the car is warmed up, so I don't worry much about it. When first setting out I use the J shifter to get a few more RPM before shifting to keep the pump speed up and the pressure a little higher. Been babying it for probably 20k miles that way.

When it finally does give up (or it gets too annoying) I have a rebuilt torque converter to throw in there.

 

What about shuddering when the transmission is really warm? After driving in 105+ degree heat (F) from Las Vegas towards Los Angeles for about 3 hours this past weekend, my ZF6 trans shuddered a little bit when I accelerated to pass a car, downshifted through 5th to 4th, and then would not go back to 6th when I eased up on the throttle. I got the dreaded "Transmission Fault" error (with a yellow light) until I pulled over to the side of the road, shut the engine down and restarted it. Then I had to baby it to my destination. It was ok after resting/cooling down for a few hours, and I was careful not to flog it on the way home. Any clues? When I had the trans fluid replaced a few months ago, the independent shop just drained and refilled. Could the trans fluid be a bit low?