Section 17 (Locking Hubs - Automatic): Description
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 1988 GMC Suburban, 1988 GMC S15 Pickup, 1988 GMC S15 Jimmy, 1988 GMC Pickup, and 1988 GMC Jimmy. However, it is still accessible from the selected car via links, so may be relevant.
The automatic locking hub automatically engages to lock and disengages to unlock the front axle shaft to (or from) the front hub. Shifting the transfer case into 4WD immediately engages automatic locking hubs.
Hubs remain engaged even during coasting or downhill operation. Automatic locking hubs disengage when the transfer case is shifted into 2WD, and when vehicle is slowly moved rearward several feet.