Yea, My Gwagon caused a pants soiling when the t-case disengaged and took the lockers with it. The system, is three buttons on the dash that use a card to limit the actuation sequence and control three pneumatic valves that in turn go amplifiers that work on vacuum from the engine. They in turn use hydraulic fluid to push and pull the dog teeth. The t-case is vacuum engaged. I guess MB knew there would be scenarios where engine conditions may not be ideal and there's a booster pump involved also. I found out I developed a small leak, when on a steep climb I found myself needing the front locker, I pushed'ed da button, it engages, vacuum drops below the minimum needed to keep the tcase locked, it disengages, the card sees it, and it opens all the valves. I'm glad there wasn't a car behind me because it was hard reverse or roll. ... Give the G460/461/Pinz master/slave setup anytime. It's on demand and bombproof. Oh, and I think the G indicates in/out with a physical switch connected to the engagement ring.
