Okay, so here is another update.

I have dropped the pan and pulled the valvebody off. I have checked that rubber seal that I have circled in the previous post and it is not it, Rubbber is soft, does not seem deformed in any way. I have also compared it with another one I had from the other transmission and they were identical.

So I have decided to try to slap on the valvebody that i havent messed with from the junkyard transmission that I have mentioned couple times earlier to see if something changes.

And something did indeed change. Now I am not only getting ganguberwachnung 5 , I am also getting ganguberwachnung 3 error.. and it shifts like complete garbage.. 4th gear comes with a bang and shift to 5th seems really delayed so not too much luck today.

Thats it Im buying new valvebody. I think that it is the root of my problems and also caused forward clutch to burn. Valves themselves are not worn but bores are quite loose.