The entire rear hub and bearing are one unit, fully sealed and sealed to last as long as the truck. You don't need to check or add any lubricant. You must replace the entire assembly if the bearing stops working or is broken. Start your work by removing the rear wheel lug nuts, lifting the vehicle's rear end using jackstands, positioning the front wheels with blocks to stop the car from rolling. First take out the wheel. Then take off either the brake drum or disc. You need to take out four backside bolts that attach the entirety of the hub assembly to the knuckle, and then you can freely lift off the hub assembly with its bearing. If equipped, remove the O-ring. You put the hub bolts in, followed by installing a fresh O-ring when needed and tightening the hub. On rear models, you need to tighten the bolts that hold the caliper bracket in place. Next, put the wheel back on and screw the lug nuts. End by lowering the vehicle onto the ground and firmly tightening all wheel lug nuts.