Mate has an E28 520i with a ZF 4HP22, it's the normal version not the EH with the electronic control and S/E/123 switch.
It was fine until he had the fluid changed, I'm guessing the change loosened off all sort of old junk and it's ended up in the valve bodies. It not jerks and changes gear when it feels like it. Car is no longer safe to drive.
My question: If I drop the drain pan I think I can remove the control unit and valve pack (if my memory is correct). Would I be able to clean this out and do you think it would do any good?