GMC Envoy Archives - Transmission Digest
The NVG 120 Transfer Case: Simple Complexity

Such is the New Venture Gear 120 transfer case (Figure 1). This one-speed all-wheel-drive unit has no electronics to operate, and no internal clutch pack or viscous coupling. It was used in Chevy Trailblazers and GMC Envoys from 2006 to 2009. Requiring no driver input, the unit uses an internal planetary-type differential (Figure 2) to bias torque between the rear and front axles.