I have seen many videos like that one, beautiful engineering and tranny looks like a cool mechanical clock but perhaps more complex.
I noticed how they test the play of tranny centre axis at the end of complete overhaul with special tool.
My issue is actually removing tranny from car, how to separate it from engine and what screws to remove, is tranny going to be simply dragged to the rear to be free... etc
There was a thread about removing another type of Mercedes transmission on a mbworld but photos were linked and host deleted them.
That is really something missing in all forums, would be nice to have.
Where I am right now allows me easy access to transmission, exhaust is out, car is raised.
the 722.6 as far as I know is more simple, valve body control unit doesn't need special coding, and it has bearings on pump instead of the bushing which was a mistake in early 722.9, they replaced it with a bearing later on.
the pump problem on 722.9 from my researching can cause breaking of pump gear and/or damage to bell housing, worse it can cause damage to planetary gears, in that case bell will need replacing/machining/ lining with aluminum plate to cover scratches (I am skeptical of that improvisation)
I have been spending the recent weeks watching videos and this would be a fun job, I just don't want to mess it up. Maybe I can get to the rear main seal and preventivly replace the seal on it as well.