BMW 325is Wheel Bearings Replacement at your home or office.

How do mechanics replace wheel bearings?

The complexity of wheel bearing replacement varies greatly depending on the vehicle make, model, year, the wheel position (front versus rear), and the drive type (AWD versus FWD):

• On vehicles with unitized wheel bearing/hub assemblies, the brake rotor and caliper are removed.
• The large axle nut is removed, the axle is pushed back through the center of the unitized hub assembly, and three (or more) bolts holding the hub assembly to the steering knuckle are removed.
• The hub assembly is then removed from the knuckle. On installation of the new hub assembly to the knuckle, the bolts are torqued to the factory specification. In many cases, it is required to discard the old axle nut and replace with a new one. Special attention must be given to tightening the axle nut to the exact factory specification because over or under-tightening can damage the newly installed bearing. All YourMechanic professionals use calibrated torque wrenches on these critical fasteners.
• Finally, the brake rotor and brake caliper are re-attached, the wheel installed and the car is road tested.
• On vehicles where the wheel bearing is pressed into a cavity within the steering knuckle, the steering knuckle must be removed from the vehicle in order to press out the old bearing and press in the new bearing.
• On some vehicles, the wheel bearing is pressed onto an axle shaft and thus the axle must be extracted from the axle carrier. This will apply to certain trucks.