Time: 15-30 min

Difficulty: easy

Cost: $50-100

If you're having 4x4 engagement/disengagement issues, a "Service 4 Wheel Drive" message, or getting diagnostic trouble codes C0378 or C0379, there's a good chance the front axle 4X4 actuator is to blame. The repair process is the same across several GM 4WD products, including: Sierra, Silverado, Escalade, Suburban, Yukon, Tahoe, Avalanche, Colorado, and Danali. The actuators differ slightly in part number, but the method is the same across many years (1999-2014).

This would be a great time to perform a front differential service as well. 

Watch the video below to see how the front differential 4X4 actuator was replaced on a 2011 Silverado 1500.