Four-Wheel Drive Systems - All-Wheel Drive (AWD): Notes
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The AWD transfer case is a two-piece aluminum, chain-driven, viscous clutch-type unit. In this system, AWD is always activated. This AWD is automatic and has no external controls.