[QUOTE=Six Rotors;1259907]
I think we all agree on that point - since ZF has only published one set of gear ratios for all the 6HP26s, it would make sense that they are all similar mechanically. However, the ZF 6HP26-28 parts catalog states that the torque handling capability varies from 326 ft. lbs. to 444 ft. lbs. and is "Model specific." (see page 4 of the pdf manual). But reviewing the parts list doesn't seem to give any clues as to what parts might change to vary the torque handling capability. Does anyone have any ideas?

Other than the Mechatronics, the only transmission part listed specifically for Ford versions is a shaft seal. Perhaps the Ford/Lincoln versions use a different driveshaft connection?

The Mechatronic is the combined valve body and Transmission Control Module/ECU, and it appears that this is where the principle differences are between the versions for Jaguar, Ford, BMW, and others, since the part numbers for all the makers (and in some cases different car models) are different. Whether the software is the only difference or there are other variations, such as valves, solenoids, etc., I have not been able to determine because ZF does not offer individual service parts, only complete replacement Mechatronics. The only mechanical differences between Mechatronics I have been able to confirm are between the E-shift and M-shift versions and have to do with the means of communicating the selected gear position to the Mechatronic.

See the email from Klaus at CTSC in my post #110 below for an explanation as to why the Mechatronic software programming must be done for use with a specific transmission fluid. Since the published specs for Mercon SP do not match those for Shell M1375.4/LifeGuard 6, it does not appear that the fluids are the same as some have claimed (though Partick has calculated the variation in published specs at just 2%). We also do not yet know if the slippage characteristics are similar enough for the Jaguar software to truly work optimally with Mercon SP.

I wonder if we could track down the actual engineers at ZF and Shell who worked together on M1375.4????

Cheers,

Don

 

I think we are "overthinking" this.


How many transmission fluids do ZF recommend for all their 6HP26 transmissions? I only know of one.


Is the 6HP26 transmission used in the 2005-2008 Lincoln Navigator made by ZF in Saarbrucken? Yes. Was it filled with Lifeguard6 at the factory? Likely.


Could Ford sell Lincoln Navigators with ZF 6HP26 transmissions and charge North American customers $65 per US quart? Not a chance! Hence Mercon SP.


I found this: http://www.audiworld.com/news/00/zf/content.shtml

 

Oh I forgot--it may be worth doing a survey of owners with 6HP26 transmissions and find out how many are running Mercon SP, for how long, and the number of failures suffered.

 

I agree.

There are going to be slight variations between the properties of the oil Shell make in the US and that which they make in Europe, partly because they are different plants and different batches, and partly because it's different labs doing the analyses ... but a 2% variation in viscosity is zippo.

Remember also that Ford is a very big multi-national and can drive a hard bargain with ZF in respect of what oil they recommend; harder than smaller individual European and Japanese companies can.

As to the claims that ZF make for LG6 ... it only really matters while the box is under guarantee many of which will expire before a fluid change is necessary ... after that their claims for it's superiority are just a marketing ploy, I would suggest.

After all, if they really did have some 'magic' additive that did significantly improve LG6's properties then ZF would doubtless share that with Ford (indeed they might be contractually obliged to do so). The last thing both ZF and Ford want is Fords with ZF boxes going prematurely '**** up'.

IF Mercon SP were available here in the UK at US prices I would be more than happy to use it, but sadly it ain't, so I will go with LG6.

But as for other companies' claims for their LG6 equivalents ... now that's a very different matter.

 

I have a 2009 XF and I have been having the similar issues, clutch plate humming, bump from behind at stops, Gear box fault message, transmission stalling at take off and now it is stuck in drive and lever wouldn't go to park.

 

[QUOTE=excelemp;1266721]I have a 2009 XF and I have been having the similar issues, clutch plate humming, bump from behind at stops, Gear box fault message, transmission stalling at take off and now it is stuck in drive and lever wouldn't go to park.[/QUOTEe ]

Just changing fluid filter and flushing fluid will not fix all these issues. Are you sure the unit is full? Low fluid could cause this.

 

[QUOTE=Panelhead;1266737]I've weighed in on this issue which seems to be a common problem with Jaguars and/or the ZF 6HP26. I'm amazed that so many people on this forum suggest that you should only use the expensive ZF fluid when servicing the tranny. I had these same problems more than a year ago and serviced the tranny myself with Ford Motorcraft Mercon SP and had no more problems with the transmission after a year and a half and 20,000 later. My problem now is that I've blown a head gasket at 192,000 miles. Let's face it. Even though the car is in pristine condition it's not worth fixing. I really like the car and for the most part it's been a pretty good ride to be such a complicated machine but I've decided to sell it to a salvage dealer. Too bad I can't buy a Corvette LS3 crate engine and 6L80 transmission in but with all the interconnected electronics on todays cars that's not an option. Too bad. Being a lightweight pushrod engine the LS3 would fit handily where the bulky old DOHC 4.2 V8 now sits.

 

OT, how much is it worth salvage and what is a head gasket replacement?
Agree that at 192k the cost to keep on the road will escalate. Many items are wearing out.

 

My point in all this is that a Jaguar is very expensive to repair and there's nothing on the vehicle that's superior to many cars costing 1/3 as much. I had a 1999 Buick Regal that went 245,000 miles that had no mechanical problems. Transmission, engine etc. were both performing as like new when I sold it. I currently have a Ford Expedition with 240,000 miles. The 4R70 transmission shifts like new and the only problem with the engine was a blown spark plug at 195,000 miles. If I ever buy another Jaguar, it'll be an old, restored XJ 6 or a Series 1 or 2 E type.

 

I found the shift lever mounting bracket had one loose bolt in my XJ. The other was still tight. But if it came loose, it could cause some agony I would think. So I'd check that first. You can see it from underneath. Two small bolts on side.

 

Stupid question...

If I maintain my car at the dealer and do all recommended service; will the tranny fluid ever get serviced?

 

Owning a Jaguar is not for the faint of heart.
Also many cars more expensive than a Jaguar are more costly to operate.
As an example take a Ferrari that costs 6 times what a Jaguar costs new. Its cost to operate is about six times what it costs to operate a Jaguar.

At the same token, Consumer reports show many inexpensive cars that have an excellent reliability record and cheap to operate.

To each his own.

 

Possibly, but probably not. They tend to be pretty hopeless with transmissions.

 

Since the Jaguar service manuals for the X350 stated that the transmission was "filled for life," it is unlikely your dealer will service the transmission unless you either complain of a malfunction or request a service.

ZF, the manufacturer of the transmission, originally specified that it was "filled for life," but subsequently revised its service specifications and now recommends the fluid be changed every 50,000 mi./80,000 km to 75,000 mi./120,000 km, or after 8 years at the latest. See this document:

http://www.zf.com/media/media/docume...hselkit_EN.pdf

Cheers,

Don

 

Jaguar's site says to service the trans (change fluid) but I believe many dealers are "poor" at reading such things.

Think of dealers as sales places which do very basic servicing (oil, filters, brakes, maybe even coolant) and you'll not go far wrong.

 

Another stupid question.... What is best place to perform such service? Transmission shop like Edwards? Jag dealer? Lincoln dealer?

Should I just replace the fluid? or the fluid & filter? Any estimate on cost? And please no DIY, this is too risky to do when a bad outcome is $2-4K. BTW, my car shifts very well so this purely preventive.

 

Here is the link for the supplies

6 Speed oil change kit Jaguar

I had an independent shop that only works on Jags and Land Rovers do the work. You will save a bundle if you buy the parts yourself. If yo are changing the fluid, might as well change the pan/filter (one piece).

 

See attached ZF publication recommending Lifeguard 6 transmission fluid for ZF6HP26 installed in Ford/Lincoln vehicles.


So tell me again why Ford Mercon SP will not work in in a Jaguar ZF6HP26 transmission.

 

According to BMW forums and other forums... Ford Mercon SP is LifeGuard 6. Mercon SP is made in Texas and thus cheaper in the US than European made LG6.

 

According to the actual Material Safety Data Sheets for Ford Mercon SP and ZF Lifeguard 6, they are not the same fluid. Their published specifications are similar but not identical. We've posted the specs in at least one of the threads here in the forum, but you can find the MSDS's with google.

There is no question that Ford uses Mercon SP in its ZF 6SHP26 transmissions and some of our forum members are using it in their Jaguar ZF 6HP26 gearboxes with apparent success. Note that the model number for the Ford transmissions includes the letter S, which does not appear in the model number of transmissions used by the other manufacturers, including Jaguar.

Somewhere in the forum I have published the email responses I received to my inquiries on this topic from ZF directly as well as from authorized ZF repair shop California Transmission Supply Co. According to both companies, Ford programs their Mechatronics* for the slippage and other characteristics of Mercon SP, while Jaguar, BMW, Audi, Land Rover, Bentley and others program their Mechatronics for ZF LG6.

The differences between the fluids may be very slight, and given the adaptive capabilities of the Mechtronic unit, those differences may ultimately be of no consequence. Or, they may lead to a slow and gradual failure of the transmission. Neither ZF nor CTSC condone the use of Mercon SP with a Mechatronic programmed for LG6, so until we know a lot more about how Jaguar boxes do on Mercon SP over tens of thousands of miles, I'm going to stick with LG6. The ultimate difference in cost is minimal given that the fluid is going to last 50K to 75K miles.

Cheers,

Don

*The Mechatronic is the combined valve body and Transmission Control Module in the ZF 6HP26.