I didn't read all of the posts. So don't chastise me if I am repeating info. I own a 01' Grand Cherokee Lerado and it is all wheel drive all the time. From what the book reads it transfers torch from a spinning wheel to the rest of the tires when needed. I love the way it handles in the snow. Good luck to yours if you get it.

01' TJ Wangler, 6" Ruff Country X Series, 35" x 12.5" Mickey Thompsons On 15 x 10" rims w/ simi Bead Lock, Matching Warn Bumpers, 9500xi Warn Wench, Tom Woods Drive Shaft And SYE, And A K+N Cool Air Intake. Still Improving