Just recently a larger transmission rebuilder shop said that early model ZF 6 speed transmissions are upgraded when this shop rebuilds them. (This shop is a local independent one -not a chain company store).

He was aware of 2004 model year cars being the the 1st XJ8 Jaguars using this transmission and said the early transmissions had several problems. And that his shop upgrades these early rebuilds with newer spec parts that improve reliability.

He also stated that one of his rebuilds should go at least 50k miles if well maintained. And that it is important to change the fluid & filter every 50k miles. I asked if 30k change intervals were better (@ $450-500 per change) and he stated this "wasn't needed."

Is he correct, can updated spec parts be used to rebuild early 2004-2005 ZF transmissions for improved reliablity? When I asked "what parts are these? He couldn't answer and said it depends on what the tech finds and replaces, but he couldn't named parts because he's not a tech.

One of his transmission rebuilds cost about $4700 - so his charge seem steep. What does everyone think?

Thanks,

Chasgood

 

If one of his rebuilds only lasts 50k miles and costs $4700, I'd ask why one of his rebuilt transmissions only lasts an oil change.

 

That WAY too much and sounds like the Jaguar = rich dumb guy price.

The 6HP26 is a common transmission and also pretty well built. Save a few minor differences it is the same transmission as the 6HP28 used in the XKR-S that holds up to 550HP. The early ones did have a few minor problems and the design was revised, but nothing too serious.

Just for your reference, this is one source for parts:
6HP26/28/32: The CTSC - ZF Parts

A full seal kit is about $225. Standard clutch kits are ~$200. Heck a fully rebuilt mechatronic unit (valve body) is only $1500. The rest of that $4700 is for his new boat.

I had done some research and it turns out that the 6HP26 and Ford 6R80 are brothers and most of the parts will drop right in. If you want to get serious about the clutches, you can go for:
EXEDY Automatics | 6R80 - 6HP26 Ultimate Performance

This is the stuff that the 1000HP Mustang guys run.

If you want to see how it goes together I had posted a link to a rebuild video a few weeks ago:
https://www.jaguarforums.com/forum/j...ebuild-107054/

 

You can replace filter (with pan), sleeve & fluid every 50-80K miles. Probably nothing else needed. DIY info in various places (S-Type, XK, youtube). Any good shop can do it. Don't buy his new boat for him!

 

Depends on what sort of upgrades you are looking for....

Have a look at these threads from other forums.

Gearbox service at ZF Dortmund, Germany

And

My visit at ZF Dortmund for Gearbox maintenance.(very, very long!) HUGH RESULT!!

The performance-oriented upgrades are not going to be necessary for our cars. Unbreakeable input shafts & heavy duty clutches like from Nizpro or Exedy aren't needed until you have serious power.

But some of the little tweaks & replacement items in the Mechatronic that they mention in those threads, they're probably more worthwhile.

But check out the costs those guys mention for the service in Dortmund!

 

Hi,

Thanks for everyone's helpful responses and information. It looks like Jaguar transmission shops can be a soakem wharf for the unwary just like many other car brands.

From your information - it seems that beyond the early 2004 cars the ZF 6 speeds should be pretty reliable.

The particular XJ8 is a late 2004 model made when that car's transmissions were supposedly alreay upgraded to fix the early 2004 problems.

I supose that somehow Jaguar could have found a left over early ZF unit and put that in instead of the upgraded unit. Seems unlikely but I know this car had some pretty good maintaince & care. The failure happened at 82K miles and there probably wasn't a fluid change @50k since the Jaguar dealer did the maintaince.

Besides the fluid changes it seems even newer XJ8 - from 2005 to 2007 need periodic trans control modual (computer) "reprogramming or re-flashing"

What is a reasonable charge for this service? Seems like the dealer is often the only shop with the necessary equipment and software to do these services. Independent shops can't do the work because they don't have the technology.

That's a real opportunity for price gouging.

thanks,

Chasgood

 

I'd expect such a service to be ~$150 to do a software upgrade and drive the car through the adaptation procedure. Any independent with a WDS/IDS should be able to do it.

I am not sure I would go so far as to say that they need it periodically though. Early versions of the software did have some issues with the adaptive algorithm drifting, which is what the reflash TSBs were about.

The adaptation should not really need to be reset unless something has changed. For example, if you replaced the clutches or rebuilt the mechatronic, you would want to reset the adaptations.