I know this issue has been discussed at some length, but I can still draw no definitive answers. Here is what I have found or determined: Jag TSB JTB 000 70 V1 addresses the issue of theh transmission chirp by saying (in 2007) that the remedy, which seems to be caused by the material which is used in clutch E1 and which was updated (presumably after the problem was identified) after a certain serial number. This included my 2005 XK8. The solution was to drain a litre of tranny fluid and replace it with a certain Lifeguard Fluid 1. There were rules, in that it could only be done as a cure for cars with ZF 6HP26 boxes having the correct serial number band and with owners complaining of the problem. I know of no other TSB that addresses the issue. The fluid could not be used at any other time or manner. Problem is: the fluid can (evidently) no longer be obtained. Changing the tranny fluid has been suggested, with the idea that ZF Ligeguard 6 (now, at least) contains the required additives, but that raises the question of the fluid that remains in the torque converter and the cooler and lines. I find no suggestions as to a practical method of backflushing, using the tranny cooler lines. Hence, only an 'atritional' method presents itself; drain / refill, run the car about for a while... repeat. All the while, there is no guarantee that using ultra expensive LG6 fluid alone will cure te problem. At a minimum of $30 / litre this doesn't feel right. Next, it is clear enough that Ford uses the same box in Navigators and others, and that they use Mercon SP (at $8 a quart). Good for goose and gander? Of course, I don't know 1) are the clutch materials and boxes identical? 2) Will Mercon SP (or any other fluid claiming to meet the specs) alone fix the chirp problem. It seems than someone somewhere must have solved this satisfactorily, and I would be most grateful to hear what was done. Thanks.

 

I just had my 03 (ZF) pan dropped and the 7 or so quarts that leaked out replaced along with the pan/filter and upgraded bolt kit. My trans was doing all the stuff found here on this site and in the TSB descriptions of the day. My car is doing great now.
A very few have had to change the fluid twice to get the trans working like normal, I guess the fluid was so bad that the 2nd pan drop got most of the rest out of the system?

 

And YES many have used Mercon SP with NO issues. Unless you have other mechanical issues which I would think not you are over thinking this. Change the fluid and see how she acts then. More then likely that is all you will have to do.

 

I run Mercon SP in both of our ZF 6HP26 boxes. Absolutely no issues and the infamous "ZF squawk" disappeared immediately in both cars after the initial drain-and-fill. I did two drain-and-fills about 5,000 miles apart on my 2005 S-Type (just turned 96,000 miles), and I'll be doing the second drain-and-fill on my wife's 2006 XK8 (approaching 104,500 miles) this coming October after doing the first one in early April 2016....

Grab some Mercon SP and just do it. You'll be glad you did....

 

I assume if a 2nd drop and fill is done you can use the same pan/filter? I would not mind trying to get more of the old fluid out.

 

Having recently purchased a 2004 XKR with very low miles and with this problem, I am very grateful, Atlastajag1, for your post.
I've driven around 1500 miles and this chirp continues to haunt me. I was thinking since the car has so few miles on it perhaps driving it would stop the chirp. But now I feel I can go ahead and do some sort of replenishing.
I will keep a sharp eye on this thread for further comments.

 

many will say here that with most any part/system on these cars, LOW MILES do not equal less issues. These cars are old now. Mine used to just hard shift in first then I heard the chip start, that is when I finally went and had the fluid/filter changed, no more hard shifts or chirps.

 

Hee, hee...Just called the local Jaguar dealer to get pricing for a flush and filter change.
Nope, not recommended! It is filled for life. Jaguar does not even offer parts for this.

...but I have a chirp...Tough! We would put a new transmission in it.

OK, back away from the phone.....

 

and Atlastajag1, I found the Lifeguard Fluid at Atlantic British parts, under Rover parts.
$23.95 with a hefty shipping fee. Is that the proper fluid?

 

ANy European repair shop near you should be able to do this maint job. DON'T bother with dealers. that said I did pay 850 bucks or so for min job on my car at my local INDY shop, had two shops quote it, came out at 850 range. Some here say it can be done cheaper or even do it yourself.

 

If you didn't know "sealed for life" was no more then a sales gimmick back in those days, looking back at them now.

 

Hey brg--no luck still in selling your car? Maybe it is an omen that you are meant to keep it

Doug

 

Everything is for sale for the right price. ha ha ha
Taking it on 600 mile round trip this weekend. Longest one we will have taken it on. Buying a Miata with hardtop from the inlaws at a family discount I can't pass up.

 

Many thanks to you all for your ideas and contributions. For Verdeo, the primary issue is 1) whether Mercon SP will damage the 6HP26 autobox, and 2) if it will not, does it contain the necessary friction modifier additives to make the squawk go away. Many peope are terrified by the sales hype from ZK and the dealers (who, to be fair, don't want people ruining their boxes by sticking any old ATF in there, but on the other hand, given the enormous prices being charged - got away with, apparently - have a lot to gain by the aforementioned). Given that Ford owns the Mercon lable and use Mercon SP in their vehicles that use the ZF6HP26 box, I cannot believe that Mercon would do the box any harm. There is the question of compatibility, I suppose, given that a lot of old fluid will remain trapped in the converter and the radiator cooler. Based upon what has been said, and given that the cost of Mercon SP is a third of the best price I have seen for Lifeguard 6, the financial risk seems low, and the mechanical risk, I am persuaded, is zero. If Mercon SP doesn't stop the chirping and squawking, I still have the L-G-6 option. I will report the results of my change to Mercon SP in due course. Thanks again to all of you.

 

there has been a lot of talk here on the Mercon stuff and the 03-06 ZF units and it NOT hurting the trans. That may be why you are not seeing many replies here. Folks are tired of talking about it when there are threads that can be searched here and read up on.

 

I had my pan/filter changed a week ago and 6 qts replaced at a local Ford dealer that's experienced with the ZF transmission. Will schedule a second drain and refill for next week at the same dealer. Still have a couple minor shifting quirks so I'm hoping the second drain will clear those up. I paid $250 labor for the pan/filter replacement, all new bolts installed and refill. I expect the drain and fill this time around to be cheaper since they don't have to remove the pan this time. May have them do a differential fluid change at the same time. I bought all the materials online and brought them in for the appointment. Hope this helps.

 

If that does not work, another option is to get the adaptations re-set. This is a procedure involving running the "factory" software connected to the diagnostic port.

 

I read on one of the TSB's for this ZF issue that if that has been done once that it should not be done again. When it is done by a dealer there would have been a sticker put on the pan/up on the side of the trans (I forget where). Call Jaguar USA they would be able to tell you anything a dealer has done to the car. My car has not had the trans reset yet.

 

Not sure what you mean by "done", brgjag. Fluid changed... or that magic transmission fixer that is not available anymore.
I don't see how a flush and filter change would jeopardize anything. In post#15 you said that changing fluid would not hurt anything.

 

I believe that is the software update option, which is new code that runs as firmware on the transmission module. As you said, this is a one-time thing done by a dealer.

Separately, the transmission can be made to re-learn to shift smoothly. It starts by re-setting the existing adaptations after a fluid change (driving the car through a predefined set of gear changes, as instructed by the factory software), and then letting the car continue to change these software parameter for the next 100 miles as you drive it. The idea is that as these parameters are eventually set to how YOUR particular transmission behaves with YOUR fluid and wear level, not some fixed generic factory values identical to every one else's.

The issue is that these parameters become basically fixed after 100 miles, but as the fluid ages and the clutches wear out, these parameters become slowly less and less suitable, and the transmission shifts more rough.