Is only one metal gear needed to open the head cultist's door over in machine town?

I've already secured one from the western hell-marsh, and that doesn't seem to be doing the trick. I'm having quite a bit of trouble finding any more gears... so... I guess I'm really stuck here. (and probably missing something obvious)

ok go back to the door in machine town and press "up" on the machine to the right of the door

Really?

Jeez... that would probably be funny if I didn't spend a good hour or two looking around for a second / different gear.

Ugh.

Well, thanks for the prompt response. It's good to be able to finally open some of those silver doors I've been seeing.