Wondering if subject is possible for X350 XJ? Both boxes are from jags.

 

Nope. The TCM and mechatronic units are different, they are not interchangable, and you can't program 6hp28 to work on a x350 CAN bus.
If you want a stronger tranny it's better to go an EXEDY route.

 

MoscowLeaper

Thanks! I don't need stronger yet, just would like faster shifting and overall operating. Even trying to feed mechatronic by x350's TCM i have zero chances? As i understand the mechanical part of 6hp28 transmission can be swapped (to make it stronger)? But the mechatronic is the point of my target..

 

It can be swapped, but it will fail sooner or later w/o a correct mechatronic unit.
Change fluid/pan+filter, reflash TCM with latest s/w, erase adaptations and perform an adaptation procedure with SDD (tricky enough).
To be honest i don't have any issues with operating speed and quality.
If you'd like to we can continue in e-mail, on russian language
nick at oldjaguar dot com