Older Chevrolet four-wheel drive pickups use a manual locking hub that's mounted to the front axle. These hubs need to be turned by hand to engage the front axle, which is then used in four-wheel drive mode. When there is a problem with the front locking hubs, then they need to be removed from the vehicle so that they can be replaced. The first step is to remove the old locking hubs.
Lock the front hubs by turning the handle in the center of the hub to the "lock" position with your hands.
Remove the cap on the hub with a hex-head key. Pull the cap off of the hub and then remove the snap ring underneath the cap with a pair of snap ring pliers.
Take out the outer clutch retaining ring and actuating cam body with the snap ring pliers, then remove the axle snap ring as well. Pull out the entire assembly from the front axle.
