APDTY 711216 4-Wheel Drive 4x4 4WD Auto Locking Hub Axle Actuator Front Left Or Right 2004-2015 Ford F150 Pickup 2003-2015 Ford Expedition or Navigator or Mark LT Pickup (Replaces 7L1Z-3C247-A) Restores 4WD 4-Wheel Drive Option From A Failed Locking Hub Commonly Needed From A Vacuum Failure