Front steering knuckle — removal and installation (BMW 3 Series E46)

Note: You will need a new strut to steering knuckle bolt and lower ball joint nuts for installation.

Removal

1. Apply the parking brake. Raise the front of the vehicle and support it on stands (see "Lifting and installing the car on supports"). Remove the corresponding front wheel.

2. If you are installing a new steering knuckle, remove the hub first (see paragraph 2).

3. If you are not replacing the steering knuckle, remove the two bolts securing the brake caliper bracket to the steering knuckle and remove the caliper assembly. Use wire or twine to tie the caliper to the front suspension spring, without tensioning the brake hose. On ABS models, also remove the wheel sensor (see paragraph 20 of chapter 9).

4. Unscrew the nut securing the ball joint of the steering rod to the steering knuckle. Separate the ball joint pin from the lever using a puller.

5. Loosen the lower ball joint nut and separate the ball joint from the steering knuckle using a puller.

6. Unscrew the bolt securing the strut to the steering knuckle. Lower the steering knuckle down and disconnect it from the strut. To make removal easier, use a large screwdriver to spread the steering knuckle clamp apart (Fig. 3.6). Be careful not to spread the clamp more than necessary to avoid breaking it.



7. Inspect the knuckle for damage or wear. Replace the knuckle if necessary.

Installation

8. Before installation, clean the threaded hole in the knuckle for the tie rod bolt using a tap of the appropriate size.

If you don't have the required tap, you can clean the threaded hole using an old bolt by sawing a groove in it across the threads.

9. Place the knuckle on the lower arm ball joint pin and screw on a new nut.

10. Align the knuckle with the suspension strut. Make sure that the strut mounting pin fits into the groove of the steering knuckle clamp (Fig. 3.10). Raise the knuckle until it stops on the strut. Screw in a new pinch bolt and tighten it to the specified torque.



11. Tighten the lower ball joint nut to the specified torque.

12. Insert the ball joint pin of the steering rod into the steering knuckle arm, then screw on a new nut and tighten it to the specified torque.

13. Install the new hub (see paragraph 2).

14. If the hub was not removed from the steering knuckle, reinstall the caliper. Make sure that the pads are correctly positioned relative to the brake disc. Lightly lubricate the threads of the caliper bracket mounting bolts and tighten them to the specified torque (see chapter 9).



15. Install the wheel, lower the vehicle to the ground and tighten the wheel mounting bolts to the specified torque.