FIREBALL said:You're pretty much right on. The air comes in through the housing, then to one side of the carrier near the bearing. (like the air hose reel you were talking about)
They work very well, although sometime (rarely) will develope a leak internally that can be pretty anoying.
Toyota has a factory locker that originally was cable operated, moving an internal fork. But since the late 80's they've come with a small electric motor to actuate the the fork. 4Runners, Landcruisers and Tacomas are available with them.