Wheel Hub: Description and Operation

A Unit III Front hub and bearing is used on all vehicles. All hub and bearing assemblies mount to the steering knuckle the same way, but vary depending on the wheel size on the vehicle. Vehicles equipped with 14 inch wheels have a 4 inch wheel mounting stud pattern. Vehicles equipped with 15 inch wheels have a 4 1/2 inch wheel mounting stud pattern. If a hub and bearing assembly needs to be replaced, be sure that the replacement assembly has the same size wheel mounting stud pattern as the original part. The hub and bearing is serviced only as a complete assembly. It is mounted to the steering knuckle by four mounting bolts that are removed from the rear of the steering knuckle.