The front wheel bearings are permanently sealed and require no maintenance. The wheel bearing and hub assembly is pressed onto the steering knuckle and requires several special tools to remove. The bearing is destroyed when the wheel hub is removed. To remove the front wheel bearing, the car must be raised and the front wheel removed. Using a suitable drift, the staked side of the collar nut is released. With an assistant holding down the brake, the collar nut is removed using a BMW special tool. The brake caliper is unbolted and hung to the side with stiff wire, and the brake disc is removed. The wheel hub is then removed using BMW special tools and 5 wheel lugs. The steering knuckle is removed and clamped in a bench vice with aluminum clamping jaws. Snap ring pliers are used to remove the wheel bearing circlip, and the wheel bearing is removed using BMW special tools. The dust sleeve is checked and replaced if necessary. The steering knuckle bearing surface is cleaned and coated with Loctite 638®. The new bearing is drawn into the hub using BMW special tools, and a new wheel bearing circlip is installed. The wheel hub is replaced and drawn into the steering knuckle using BMW special tools. The steering knuckle is then installed, and the front axle is drawn into the steering knuckle. The front brake disc and caliper are installed, and a new axle nut is used to tighten to specified torque. The side of the axle nut is staked to the axle using a suitable drift. To remove and replace the steering knuckle, the car must be raised and the front wheel removed. Using a suitable drift, the staked side of the collar nut is released. With an assistant holding down the brake, the collar nut is removed using a BMW special tool. The brake caliper is unbolted and hung to the side with stiff wire. The front brake disc and wheel speed sensor are removed. The tie rod end, tension strut, and control arm are removed from the steering knuckle. The drive axle is pressed out of the steering knuckle, and the steering knuckle is supported using a suitable jack. The fasteners securing the front strut to the steering knuckle are removed, and the steering knuckle is then removed. The installation is the reverse of the removal process, with new fasteners being used.