Note: You will need new top strut mount nuts and strut-to-knuckle mounting bolt for installation.
Withdrawal
1. Support the rear wheels. Apply the parking brake. Raise the front of the car and place it on stands (cm. "Lifting and placing the car on supports"). Remove the corresponding front wheel.
2. When removing the rack, you must support the lower arm. To do this, screw the wheel bolt into the hub and tie the bolt to the body. Alternatively, support the lever with a jack through a piece of wood.
3. Disconnect the brake hose and wiring harness from the rack (pic. 4.3).
4. Turn away a nut and disconnect the hinge of fastening of an earring of the anti-roll bar from a rack. When loosening the nut, hold the hinge pin with an open end wrench.
5. On models with an axle load sensor (headlight beam adjustment systems) Loosen the nut and remove the link arm from the lower arm.
6. Turn out a bolt of fastening of a rack to a rotary fist. Lower the steering knuckle down and disconnect it from the rack. To facilitate removal, use a large screwdriver to spread apart the steering knuckle clamp (see fig. 3.6). Be careful not to spread the clamp more than necessary so as not to break it.
7. In the engine compartment, unscrew the nuts of the upper strut support, then carefully lower the strut down and remove it from under the wing. On some models, the upper strut mount is centered with a special pin that fits into the hole in the body (pic. 4.7). On models without this pin, mark the position of the strut support relative to the body. It is very important that the strut is installed in its original position so as not to disturb the camber angle of the wheel.
Repair
Attention! Before you start disassembling the rack, purchase a spring compression tool. The most suitable is an adjustable coil spring compressor. Other ways to compress the spring are very dangerous and can cause injury.
Note. Reassembly will require a new platter nut.
8. After removing the rack, clean it of dirt and clamp it vertically in a vise.
9. Install the spring compressor and compress the spring so that it moves away from the top seat (pic. 4.9).
10. To access the top nut of the rack, remove the cap. Loosen the nut while holding the damper rod with a suitable tool (pic. 4.10, a, b).
11. Turn away a nut and remove a basic disk together with the persistent bearing. Remove the conical washer, then the flat washer, and the upper spring seat.
12. Remove the spring, buffer, boot and lower spring seat.
13. Now the rack is completely disassembled. Inspect all parts for wear, damage or deformation. Inspect the top support bearing and make sure it rotates smoothly. Replace worn or defective parts.
14. Inspect shock absorber for leaks. Inspect the damper rod along its entire length for pitting and the damper body for damage. While holding the shock absorber in a vertical position, check its operation by moving the piston through the entire stroke, and then in 50-100 mm increments. In both cases, you should feel a uniform and constant resistance. If jerking or uneven resistance is felt, as well as if wear or damage is visually detected, the shock absorber must be replaced.
15. In case of the slightest doubt about the serviceability of the spring, carefully remove the device for its compression and carefully inspect the spring. If the spring is deformed or damaged, replace it.
16. Inspect other parts and replace faulty ones.
17. Put the lower spring seat on the rack, then the buffer and boot (pic. 4.17, a, b).
18. Put on a rack a spring. Make sure the spring is properly seated in the rubber seat (pic. 4.18).
19. Put on the upper spring seat and rotate it so that the end of the spring is against the stop of the seat (pic. 4.19).
20. Put on the flat washer, then the conical washer (concave side up) and top disc. Screw on a new nut and tighten it to the required torque (pic. 4.20, a-d). If the damper rod turns when the nut is tightened, BMW offers a special socket wrench with a cutout. You can insert a hex key into this cutout and hold the stem with it from turning.
22. Before installation, clean with a tap the threaded hole for the coupling bolt of the steering knuckle clamp, with which the fist is attached to the rack.
In the absence of an appropriate tap, you can clean the threaded holes using an old bolt by sawing a groove in it across the threads.
23. Bring the rack to the place of its installation, align the dowel pin with the hole in the body (or labels to each other) and secure the top support with new nuts.
24. Put your fist on the rack (see paragraph 3) and screw in the pinch bolt. Tighten the bolt to the required torque. Note that the wire and brake hose bracket is also held in place by this bolt.
25. Torque tighten the top leg nuts.
26. Install the load sensor rod bracket on the axle (if it exists) on the lower arm and securely tighten the mounting nut.
27. Insert the connecting hinge of an earring of the anti-roll bar into a rack. Make sure that the flat on the pivot pin is properly aligned with the strut, then put on the washer, screw on the new mounting nut and tighten it to the correct torque.
28. Attach the wiring harness and brake hose to the strut. Install the wheel, lower the vehicle to the ground and tighten the wheel bolts to the correct torque.