I think you might be right. I found something on the manual that describes this procedure, but interestingly enough it appears to only apply to trucks with auto transmissions (if I'm reading correctly).

As for the 4x4 capability of the truck, yeah it was really impressive (all things considered). Admittedly I pushed the envelope a bit, and went places that maybe I would've thought about twice if I didn't have a tractor near by that I knew could get me out of any mess. Truck handled great, gripped the ground like a mountain goat on 4L.