THEN, what controls the manual valve?

Is it a linkage or an electrically operated do-hickey?

Or is it something else?

Let's put some TRANSPARENCY on this issue instead of keeping a big dark secret so the 2 guys have to spend big $$$$$$$$$ at a tranny shop.

We have 2 people here who need help.

Any links to the "manual valve" that 'controls' the "forward drum" so we can see what it's all about?