Rock crawlers are mind-bending machines. Through the use of gear reduction, drivers can scale near vertical wall faces and get to places stock vehicles would never see. Besides the ability to help a vehicle climb ridiculous inclines, a properly sorted transfer case system can help out a truck in other ways.
Marlin Crawler demonstrates this concept beautifully. Watch the truck struggle to fire back up once it’s stopped and only the stock system is engaged. After engaging the Marlin setup, the truck practically walks up the rock walls simply by bumping the starter.
These rigs are amazing.