That seems to make sense. I would not think that, no matter whether I should or should not have- (just my stupid), that merely clearing the adaptions would all of sudden cause the clutch to go to hell. It always seems when at the 1800-2100 area to want and try to bump up the rpms before it will fail. On some occasions it will find 4th at those speeds, but right now I keep it shifting at a higher rpm and no fault and fairly smooth.

I assume that when cleared there must be some sort of default map it goes to and I would assume that it expects everything to be pristine, especially the fluid- does that make sense and so with the old fluid it has to reach out further than its default map to find the right pressure and shift points??

TBB

Thanks Scott. I will try and find it.

TBB

Looks like you are in good company-- from Brutal: "I do 3 things with this issue. and funny the most common is the 3/4 shift. pan replacement and drain and fill. 7 litres if left overnight. 6 if in a hurry. then clear adaptation and upload latest software into tcm. drive for a few hundred miles while the tcm relearns adaptations and leave out of sport or competition. avoid aggressive up/down shifts. past this you may have a valve body/shift solenoid issue. But do these first and is the recommended procedure from ZF. We don't ever do the adaptation learn with sdd. cant. to much traffic and 2 people to do, but never had any issues and I have been amazed over the years at how many cars get fixed with those 3 things when it used to be a tranny replacement"

Not to disagree with the inestimable Brutal, but in your case, Tom, I would recommend a complete flush, which will take 10-12 quarts of fluid. A drain and fill leaves about 4-5 quarts of old fluid in the system, and your goal is to help make readaptation as easy and quick as possible for the TCM. It's pretty easy to do a flush via the cooler line fittings. I'll try to post some DIY instructions.

Cheers,

Don

I have seen the cooler line idea, however I am not going to do this. There is a learning curve and a mess-up can cause even greater problems. I have the largest family owned independent set to do this job and at a great price. I really do not have the facilities for something like this. Tell me if I am wrong, but is it not bad to flush an older system completely? And is this not a fairly messy job?

TBB

Over the years I have heard many anecdotal stories of transmission fluid flushes causing transmissions to fail, but I have been flushing transmissions for nearly 40 years and have never had a transmission behave worse after the flush. Nearly always it has behaved noticeably better. This has been especially true in Jaguars with the ZF 6HP26. The things you must get right are the choice of fluid and establishing the correct fluid level. These are the same critical issues whether you do a complete flush or just a drain and fill.

Dropping the transmission oil pan is far messier than performing a flush via the cooler lines, but your shop will have everything necessary to deal with these issues. Be sure they use Ford Motorcraft Mercon SP or ZF Lifeguard 6 fluid, and that they have the ZF instructions for establishing the fluid level at the correct temperature. Also, if they are going to replace the pan/filter, they should also replace the electrical connector sleeve (which invariably leaks and allows transmission fluid to contaminate the electrical connector pins).

Cheers,

Don

Thanks. I will just let them deal with the mess and the heat. I think they use Amsoil for the foreign cars. I would also use Pentosin. I am well aware of the sleeve issue and that is a given, plus new bolts. Did you get your bolts at any special location that has them at reasonable prices- just curious for future reference.

TBB

To my knowledge, neither Amsoil nor Pentosin makes a transmission fluid that is equivalent to ZF Lifeguard 6 or otherwise suitable in the 6HP26. The only equivalent we know of that is commonly available in the U.S. is Ford Motorcraft Mercon SP. Do not use any third-party fluids that claim to be equivalent to Mercon SP because they are designed as compromise products to work "acceptably" in a wide variety of transmissions but not optimally in any.

For the pan/filter, sleeve and screws, shop our forum sponsors SNG Barratt, Coventry West and Jagbits (I think they may offer a discount to forum members so be sure to ask), and also The California Transmission Supply Company (thectsc.com), FCP Euro, etc. You typically don't need a full set of screws - but it's a good idea to have half a dozen on hand to replace any that may break or suffer head damage.

Cheers,

Don

+1 on the fluid, it's not worth taking a chance on.

Just curious, what do you do with the worms after opening the can like you just did? I'm thinking a light beer batter, or maybe panko breading. And where does one actually get a can of worms in the first place? I tried Amazon but no joy...

Flushing a transmission is a very contentious subject. Lots of over-inflated opinions online, with tales of woe. Here's one of the more down-to-earth articles:

https://wheelzine.com/transmission-flush-good-or-bad


After reading that, the proverbial light bulb over my head clicked on. I'm firmly in the anti-flush camp, fearful of solvents that may inadvertently dislodge debris, wash away varnish that's actually helping worn seals, etc. Never been around a transmission damaged by flushing, but I have personally seen engines destroyed by a similar cleaning process. That's when I realized "flush" can mean different things to different people, based on the actual procedure.

I'm still leary of machine-based flushing, accomplished with a high pressure external pump and special solvents. Seems like cleaning your kitchen with a pressure washer.

But then there's another type of flush, which is more like a thorough fluid replacement. Instead of using an external high pressure pump, you run the engine at idle and use the transmission's pump to transfer the fluid. After disconnecting the cooler lines, you pump the old stuff into one container, and draw in fresh from a separate container. I've done this procedure on other vehicles with excellent results.

I suppose some machines do the same but with an external low pressure pump. It's the high-pressure chockful-of-solvent method that gives me the heebie jeebies. Don, what kind of flush procedures have you been doing? I'll defer to your obvious experience on the subject, versus my likely-flawed opinion.

Hi Karl,

That's a very good question. The above describes my DIY method of flushing the transmission. I don't believe in introducing anything into the gearbox that is not the correct transmission fluid, unless performed by an automatic transmission expert for a very specific reason. The goal of the DIY fluid flush is to replace all of the old fluid with fresh new fluid. A typical drain-and-fill does not replace the old fluid that remains in the torque converter, valve body, and any other areas that may retain fluid when the engine is not running.

Cheers,

Don

Here is a question. This problem all started when I stupidly cleared the adaptions on a car that was working fine, but had old fluid and I understand that the TCM must be looking for some common points that the old fluid does not immediately it gets and that seems to be your reference ("Since you have old fluid now, the TCM is having to work its way toward the very limits of its adaptation capacity)"
1.Does that indicate it may eventually get it right but will take more time than my OCD personalty likes- ha!
2.People talk about a re flash and while I have SDD version 133 and I assume I can re-flash from that, but I am tentative with that in the desire not to a risk of bricking the TCM.
3.So if I get the fluid change, and reset the adaptions and then drive like an "old man" as Brutal describes will the system get the adaptions set and may just take more time. I do have the most current installed that was done by Jag to rid me of the lurch. What is my advantage to re-flashing with the same- if there is one?

Thanks

Tom

Pentosin is fine

Looks like Amsoil will fit as well.

TBB

According to Pentosin, the kinematic viscosity of Pentosin ATF1 at 40 degrees C is 38 mm2/s.

According to Amsoil, the kinematic viscosity of their ATF at 40 degrees C is 38.5 mm2/s.

According to ZF, the kinematic viscosity of Lifeguard 6 at 40 degrees C is 26.8 mm2/s.

What is fine about those high viscosities?

Lifeguard 6 is a very low-viscosity fluid, designed for the very small tolerances and fluid passages in the 6HP transmissions (which are significantly smaller than older transmissions). The viscosities of Pentosin ATF 1 and Amsoil ATF are significantly thicker and closer to that of Dexron III, which was used in the old ZF 4-speed transmissions but is completely unsuitable in a 6-speed gearbox.

We have found through extensive research that the claims of third-party fluid makers that their fluids are suitable in a wide variety of transmissions cannot be trusted.

I have found all these brand discussions to sometimes get way out of hand, but I know that people mean well.


Let me re ask the important concern that I have:

Here is a question. This problem all started when I stupidly cleared the adaptions on a car that was working fine, but had old fluid and I understand that the TCM must be looking for some common points that the old fluid does not immediately it gets and that seems to be your reference ("Since you have old fluid now, the TCM is having to work its way toward the very limits of its adaptation capacity)"
1.Does that indicate it may eventually get it right but will take more time than my OCD personalty likes- ha!
2.People talk about a re- flash and while I have SDD version 133 and I assume I can re-flash from that, but I am tentative with that in the desire not to a risk of bricking the TCM.
3.So if I get the fluid change, and reset the adaptions and then drive like an "old man" as Brutal describes will the system get the adaptions set and may just take more time. I do have the most current installed that was done by Jag to rid me of the lurch. What is my advantage to re-flashing with the same- if there is one?

Thanks

Tom

You probably haven't driven the car enough to worry too much about the current adaptations, but there's nothing to be lost by clearing the adaptations again after you flush the fluid.

OK. Do yo see any need for a re-flash of the TCM with software or will just clearing the adaptions be al that I need to do?

TBB

No. If the latest firmware was already flashed there is no need to do so again.

Whenever I 'clear adaptations' for the 6HP26 IDS will determine if the TCM and/or ECM needs to be updated.
The screen prompt will advise that the TCM and/or ECM will need to be updated and the procedure will take approximately X amount of time........ Do you wish to continue?

Make sure you have another battery connected or a power source to prevent low battery during the procedure.

If the software is current, then the 'clear adaptations' will be all that is required.

bob