Please help me find where this hose plugs into
 

I can't for the life of me figure out where this hose should plug into. It's a rather stiff plastic material and plugging it and unplugging it with my finger at idle makes no difference whatsoever.

(the one with the green dot on it)

http://i.imgur.com/VSYXDID.jpg?1

Pretty sure it's the vent hose for your front differential. Purpose it to allow hot gases that are generated during operation to vent/equalize with atmospheric pressure. It is meant to be open. See also: http://www.xoutpost.com/bmw-sav-foru...k-hose-go.html

Good luck.

I'm convinced, my mind is at ease now, thank you! :thumbup:

Seems like all new owners with the ZF trans always post this question.

Is it the transmission breather or front diff breather?

Front Diff.

The front differential is the transfer case for the X drive correct? Or is that something entirely different?

haha, i posted the exact same picture when i first got here. apparently some vent that should be left alone.

Transfer case is located at the back of the trans and provide power to the front differential through a drive shaft. The front axles are attached to the front differential.

If this front diff breather has nothing to do with the transmission, then I wonder why you referred to owners with the ZF trans always posting this question?