To do a complete rebuild the parts are $1,000-$1,500. That includes trans, valve body, solenoids, and torque converter.

Techs charge about the same to rebuild.

So you are at approx $3.000 for a rebuilt trans and another $1,000 for install.

Yes, the tranny can be rebuilt but ....
 

Most mechanics, no matter how good they are, do not have the experience or the tools required to rebuild any tranny other than maybe the 2 speed GM Power Glide.

https://en.wikipedia.org/wiki/Powerglide

To get your 6 speed ZF 6HP26 rebuilt, you have to find a very much non chain shop, (usually in the east end), surrounded by a bunch of dead Mercedes and the like.

The guys in there probably do not speak very good English but their German or Czech is great - those are the guys you are looking for, and they do exist in the larger centres.

Also the "new" Ford 6R60 is a near copy of our 6HP26 - license built and all in USA, hence shops that can do the new Ford units and rebuild the ZF.

You just have to dig about to find guys who routinely fix the ZF or Ford units.

Below is a link to a number of files I have on the 6HP26, including the Ford 6R60. I see one of the files has over 4,000 views and many including the Ford file exceed a thousand views.

DISCO3.CO.UK Photo Gallery - ZF 6HP26 Automatic Transmission in LR3

If it were me, I would take the truck to a Landy dealer and get them to update the software for the truck. These beasts are a computer on wheels and develop software issues just like your PC. It cost me $150 to get it done and my transmission, while not exhibiting the same issues as yours, improved in it's performance.

Another thing to check, or have checked at a reputable transmission shop, is the fluid level and condition of the fluid. Getting a flush done, if needed would be another cheap alternative than going the replacement route. Also, check out salvage yards for low mileage LR3's. I can't remember if another transmission can be swapped in without issue or not. One of the more learned members on here will chime in with that info.

Used trans can be swapped as long as you transplant the mechatronics to the donor trans.

I have a 2005 lr3 start slipping. A mechanic shop change all the cluch, torque converter and the car does not change from 3 to 4. He said to me that the valve body is not good. But he does not know for sure because he does not test them to see if another problem. His assumption is that if he change everything in the transmission, still doing the same thing , it should be the valve body and the tcm. Now I want to know what to do because the valve body is expensive unless I can buy a new one which require to reprogram. I want to know if I can reprogram a used one and how much or if I can find one that is compatible without programming.

anyhelp would be appreciated
thanks

Sounds like the shop messed it up good, they should fix it if it was shifting fine before.

While it was apart they should have checked the shift solenoids and then replaced all the o-rings, seals and separator gasket . Shift issues are generally valve body related.