My wife has been complaining about sporadic rough low-speed shifts in her 2006 XK8 for the past month or so. Okay, so her factory fill of ZF Fluid is more than eight years and 67,000 miles old now, so I order the appropriate kit from Klaus at thectsc.com. That's a new pan/filter, sleeve, fill plug, and six litres of Lifeguard 6. Two days ago, Rick (joycesjag) and I perform the ZF service exactly as required using the kit (thanks again, Rick). As expected, the drained fluid is a light brown color, not golden as new fluid is - the friction modifiers are certainly worn out by now. There are no metal shavings on the two magnets in the original pan. After everything is back together and 5.5 litres of fresh fluid are pumped in exactly as Klaus said it would be, my wife's XK8 is back to smooth, quiet shifting, just as we expected it would be. Great, yet another to-do task crossed off my list for this car....

Not so fast. My wife just called me saying "You didn't fix it. I was pulling away from my office and it shifted rough again in the low gears, and the 'transmission fault' message showed up on the dash. So I pulled over, shut the engine off, let it sit for a minute or two, started it back up, and now there's no warning messages and it acts like nothing ever happened. So what do I do now?"

I just told her to keep driving it, watch for messages, note the shift patterns, and keep me posted. I'll take it out myself when she gets home this evening....

So what's next from a diagnostics standpoint, guys? Do these symptoms ring a bell with any of you dealing with your six-speed ZFs? I really thought the new pan/filter/sleeve/fluid would fix the sporadic transmission issue and get my wife quiet again....

 

Ah Jon this sucks. Sorry buddy.

Have you considered talking to Klaus about this problem?

 

You probably should have the TCM upgraded to the latest firmware and have the adaptations reset.

 

+1 on that. I have a post from at least a year ago about harsh 1-2 up shifts on my 2004 XK8. The fluid/filter change did nothing to help that. I finally had the TCM reflashed and adaptations were reset = problem solved. I never had any error messages though, and I never had shifting problems other than 1 to 2.

 

Here's the link to the thread and the TSB:

https://www.jaguarforums.com/forum/x...-shifts-88905/

Graham

 

Reflashing the TCM is not a bad idea but did you do a hard reset after you did your refill? I would try that first.

 

+2 on that...TCM flash sould address it but you were due for trans service so it is still money well spent.

 

Thanks for the suggestions, guys. I truly appreciate your willingness to assist with this frustrating situation....

Rick - I did e-mail Klaus, and his response was to get the faults read before proceeding to any other repair attempts. Not sure yet who or what can read these transmission codes. If I remember correctly, an OBDII code reader will not do that....

Gus - We did not do a hard reset after we serviced the ZF. I don't have much confidence that it will fix a transmission issue, but it's free and it's fast so I'll do that today....

For a TCM upgrade/adaptation reset, is a Jaguar dealership the only option? To me, a transmission specialist with ZF experience makes more sense if they have the tools to do so....

And yes, I'm glad Rick and I did the initial pan/filter/sleeve/fluid service. At 67,000-plus miles, it was certainly the proper first step and it cured the infamous "ZF bark"....

 

I've searched this site and Gus' site using "hard reset" to ensure that I have the details exactly in order, but thus far have not been able to find a reference. I know it's here in many threads, I've read the details multiple times over the years, but just can't find it right now. Can someone list the steps for me so I can do it properly? Thanks....

 

Jon,

The definitive thread on the procedure is in the XK8/XKR FAQ's. Here's the link:

https://www.jaguarforums.com/forum/x...ect-faq-74146/

Graham

 

Remove the Negative Battery cable from it's post and then touch the cable that you have removed to the Positive Battery Post for 30 Seconds. Then, re-connect the Negative Cable back to the Negative Battery Post.

You will have to Re-Set the Window up and down limits and some of the Radio Pre-sets.

 

Hard reset done earlier this afternoon. My wife is out and about in the car right now so we'll see if anything has changed with the ZF shifts. I'm not expecting any difference....

Spoke with two Jaguar dealership service departments this afternoon regarding the ZF Adaptation Drive Cycle procedure (TSB JTB00145). Our local Cary dealership charges $213 and believes it will fix the issue. The Greensboro dealership (a little more than an hour's drive from me) charges $135 and believes it may not make any difference. They prefer to run diagnostics first and then go from there....

 

Fingers crossed on the hard reset

 

Thanks Gus, but the hard reset made no difference. Harsh 1-to-2 shifts still intermittently present yesterday after I did the hard reset per the instructions here. My wife hasn't seen any 'transmission fault' dash messages since Friday morning, though. I may have to cave in and take her XK8 to a dealership for the first time since we purchased it nearly 18 months ago....

I wonder if the torque converter or valve body are acting up. I'm assuming if they are, the fault codes would indicate so. Anyone know?

 

Jon,

From the ZF 6HP26 Troubleshooting Guide:





(click on the images to enlarge them)

Looks like you're stuck with the Dealer or an Indy with equivalent diagnostics to clear the transmission adaptions.

Do you have a scantool that can read transmission DTC's or are you thinking of using the Greensboro dealership for diagnostics?

Graham

 

Graham,

I have no scantool that can read the transmission faults. Looks like her XK8 is headed to a professional, we just haven't decided who and where yet. Have to wait until Monday before I can do some additional calling around and speaking with our potential service providers....

I certainly wish that the ZF Adaptations Drive Cycle TSB procedure would provide the necessary fix as it apparently did for others in a similar predicament. But perhaps paying for a full ZF diagnostics should be our next step. I'm still torn, and I need more information and advice before I decide what to do....

As always, thanks for your assistance and concern....

 

Update:

After further discussion with the Greensboro dealership this morning, my next step is to have them perform the ZF Adaptations Drive Cycle via IDS as specified in the TSB. They will need the car for two hours and charge me $175. Their history of fixing these ZF shift problems via this procedure is quite good over the past few years. So it's relatively inexpensive and worth a shot in my opinion....

The guy I spoke with there on Saturday afternoon was part of their GM service team, not their Jaguar service team. None of the Jaguar staff was working that day and he was not very informed on Jaguars. I thanked him for his time and told him I would call back and speak with their Jaguar service manager on Monday morning. That's what I did, I now have an appointment on Thursday morning for the job, so I'll drive over and wait on the car while they apply the TSB....

Sure hope this fixes the shift issues once and for all. Feel free to offer additional guidance, especially anyone who has experience with Flow Jaguar in Greensboro....

 

Sorry, I have one question I neglected to ask in my earlier post:

I spoke with a well-respected local British cars indy shop who claims they can accomplish the ZF Adaptations procedure using their Autologic system, not Jaguar's proprietary IDS system. Is this true?

 

They should also make sure you have the most current firmware and update it if necessary.

 

Doesn't the "Golden Rule" that Graham posted say that the adaptions should be cleared before updating, or am I reading it wrong?