Transmission Compatibility
 

Ok, Looking for some insight here. I have a 2003 S type R in the garage. No issues at all. However, looking ahead for the future, I would like to buy another ZF6hp26 transmission and slowly rebuild it and do some upgrades and have it ready for if/when the one in the car ever goes.

So here is my questions:

1. What year(s) of the zf6hp26 transmissions with be a direct bolt-in and plug and play harness wise?

2. If I can use per say a 2007 or 2008 transmission in my 2003, is there any software issues or computer related issues?

3. Is there a current list of must have upgrade parts for inside the transmission? I know the converter was an issue on the 2003/2004 cars causing the surging issues. Is that simply resolved by using a newer converter or do I need to purchase an aftermarket or rebuilt unit?

I plan on doing an AVOS twin screw in the next year and adding water/methanol injection so I need to be prepared for the additional torque/hp.

I can say that there are 2 versions of the 6hp26 and you will need to find one specified for the STR vs. 4.2 NA

These transmissions are pretty strong as designed (besides the early TC issues) a new replacement would square that away.

Another point - making sure you have the latest calibration files in the TCM. I don't believe a 07 or 08 ZF6 will be compatible in an 03 - replacement trans are VIN specific.

Taking a stab - probably 03 to late 04 or possibly 05

Besides that best maintenance to take on is to ensure fluid level is maintained and timely changes of pan/filter & fluid (every 40 - 50K miles) and to monitor for leaks (pan, sealing sleeve - very common leak area and the trans lines)

That's my $0.02 - I know others will chime in... Thanks

I just hit 110,00 miles. I changed the Transmission pan/filter earlier this summer around 90k and refilled with new fluid and new trans sleeve. It was also done around 45-50,000 miles so that is a huge plus.

I have experienced on cold days for a brief time the surging around 50 or 60mph while it is in normal mode. A quick click to sport mode takes care of it. But it does concern me if I start adding power. I do know that it has NEVER had any software upgrades.

so this leads me into another question:

is that a sign I need a new Torque converter in the near future? or simply get updated software?

Well no twin screw for the S Type and it's been promised for about 6 years now.
Are you sure you would spend the $5-6K required on a twin screw when your car is only worth about $7K?

Any car over 100K miles has very little market value.
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I believe that is the TC issue but if that's your only issue - your trans is in pretty good shape.

Not sure if a SW re-flash would cure that issue.

The car is paid for and I owe nothing on it.

Have you read the TSB that addresses this issue?

I have read many different reports of it. However I have not found the ACTUAL TSB for the way Jag wants it done step by step. Do you have a link?

:icon_steer:

https://www.jaguarforums.com/forum/s...86/#post139192

Third of five TSBs attached.

For the amount of effort you are willing to put forward, I think it would be more economical and efficient if when the time comes you actually do need a new transmission, to get yours rebuilt by a certified ZF facility. IIRC its about $4K to $5K for a used running transmission, so for that amount of money, why not just wait until the bad day comes and send yours out to get rebuilt to spec, instead of gambling on a "Certified" used tranny.

A new torque converter which causes probably the majority of "Transmission Issues" can be rebuilt for $300-$500, but a new one cost $1300 to $2000. Add up all these numbers and you are looking at a final value more than the cost of your car. I would just be patient and again when the time comes, get everything rebuilt and refurbished. The turn around time would probably be quicker for all of the above and trying to piece it together individually. Best of luck...

Definitely look into a re-flash of the TCM. I purchased my 2004 4.2 (NA) at 120,000 mi and did refill of fluid and pan change. Always had the "surge" but had ignored it until eventually I starting getting a very harsh 2-3 shift which would throw the trans into limp-home mode ("GEARBOX FAULT"), but reflashing the TCM brought it back to life and has got me to 140,000mi so far. Never did get rid of the surge though, I just live with it

rasputin_

I find used Z6hp26 trans on ebay popping up all the time for under 800 dollars. And several are listed from coming from a supercharged 4.2 and cheap freight charges. With that being said, I can get a full rebuild kit, Seals, Clutches and plates for under $350. I have rebuilt many trans over the years, many 700r4 and 4l60E. Watching several videos of tear down and reassembly looks incredibly simple. Looks easier to rebuild one of these than a turbo350 even. As long as the other components are in good shape and no obvious signs of damage, they seem to not need to be replaced.

Has anyone on here ever rebuild a ZF6hp26 trans? I would love some first hand insight :-)

You are a more ambitious man than I. So as to not completely write off my response, during my torque converter discovery process, I found a few interesting sites.

Range Rover 6HP26 tear down:
ZF 6HP26 Teardown

There are many handbooks and guides on the internet as well as on this site:
https://www.google.com/webhp?sourcei...6hp26+handbook

Also, one other thing to note is that while review some of the handbooks, they mentioned that there are Jag only tools that are needed to pull the tranny. Not sure if that is true or not but you might have to fab up your own tools to make it all work.

Good luck!

Does anyone know if the torque converter can be replaced without having to pull the engine or transmission?

I have replaced several TC's in parking lots on GM and ford trucks but this is another animal. I wonder if there is enough wiggle room to unbolt the trans and bell housing and separate the two then get to the TC?

No

I believe that the motor can stay in the car, and just by unbolting the driveshaft, bearing support, and trans mount cross member I could probably the do job in my garage if the car is up on some nice jack stands?

Some input here. I do have access to a lift but I would have to work straight though the job and I would rather do this a few hours a night in my own space.

Has anyone took this job on?

Check out the links in my other post, the repair guide shows that the tranny has to come out for the TC to be replaced. Motor stays.