AW55-50/51 DISENGAGES WHILE DRIVING

Hello!
Have read hours and hours about this gearbox problems, but not having any solutions of the same issues.

Having this problem for two gearbox changes and weīre out of thought of my mechanic friend.

Bought an S80 2005 with broken gearbox which got stone under the front end and broke the gearbox. Rebuilt new gearbox and changed clutch disks and of-course new oil. Everything worked fine until about 100km, we tried to do the Adaption, but it failed and didnīt get a change to do it next time because 1 day later it disengages in town-speed. Revs go up but moving hard and after few moments not at all. When restarting the car, it worked again for a very few moments. Thought the filter is full of mush.

Changed the gearbox (which was welded and already ready with new filter) and put the same valve body from this car. With previous valve-body it didnīt work properly.
Everything worked fine, except some harsh gear changes from 3rd to 2nd like it was before. Okay, thatīs not the problem at the moment. After 150km when got from 50km road to city, then car revved 2500-3000 some times and when stopped and accelerating it revved and moved slightly.Turned off the car but the problem was same. Managed to get home and when checked the ATF level (did it correct way), it was 3/4 inch above HOT upper mark. I let it cool down and checked in the morning it was 1/2 inch below lower COLD mark. Drove it for 15 minutes, everything worked fine, accelerated nicely but then suddenly disengages and no power, just revved. Oil level was same as last evening 3/4 above HOT.



For us it looks like electrical problem, because when cold works fine, after reaching working temperature, problems start to occur. Have read it could be TCM (Which codes it have). What to do with TCM?
Sticking Solenoids?

Donīt think itīs converter, because when itīs dead, then itīs dead but not only when in working temperature.

Any thoughts? What to check?
Thanks and waiting for thoughts.

Kindest,
Elmo

 

Seriously no thoughts?
Tried another gearbox selector switch but no luck. Bought new TCM, problem is the same.
Can it be some bad wire contact? Where to look, whatīs related to temperature and can have bad touch?
Sad to see great car standing.