Withdrawal
This Section applies to all front suspension strut assemblies, and rear suspension spring and damper assemblies.
If there are obvious signs of wear on the struts, shock absorbers or coil springs (such as fluid leakage, loss of damping capacity, damaged, stretched or cracked coil springs), check all parameters before starting any work. Struts or shock absorber assemblies with spring are available in workshops for exchange, greatly saving labor and time. Before dismantling the car, always check the cost and availability of the parts you need.
Removing the suspension strut or shock/spring assembly is potentially dangerous and must be handled carefully or serious injury may result. Use only high quality spring compression tools and carefully follow the manufacturer's instructions that come with the tool. After removing the coil spring from the strut assembly, place it in a separate, safe location.
1. Remove suspension strut or shock absorber assembly (see Section Removal and installation of assembly of a rack of a forward suspension bracket). Place the assembly in a vise. Protect the jaws of the vise with pieces of wood or rags to prevent damage to the assembly, and do not overtighten the vise.
2. Following the manufacturer's instructions, install the spring compression tool (it can be purchased at most auto parts stores or borrowed) on the spring and compress it enough to remove all tension from the suspension mount. You can check this by shaking the spring.
3. Remove the protective cap from the shock absorber self-locking nut. Loosen the nut with a wrench while holding the shock in place with another wrench.
4. Give a nut, remove the bearing of a rack, an insulator and a big washer. Check if the bearing runs easily. If it sticks, replace it. Check the rubber insulator for wear and cracks and replace if necessary.
5. Remove the spring retainer and rubber ring at the top of the spring. Check the ring for cracks and hardening. Replace if necessary.
6. Carefully remove the compressed spring from the stand assembly and place it in a secure location such as a steel cabinet.
Never tilt your head close to the end of the spring!
7. Remove the protective tube and rubber buffer from the shock absorber. If they are worn or damaged, replace them.
8. When working on the front suspension strut, release and remove the threaded collar, then pull the old strut assembly out of the strut body. Pour out the old oil from the housing.
9. On all racks, except for gas-filled racks, fill the rack body from 42 to 47 cm3 (on 518i and 520i models) or 20 to 25 cm3 (on other models) engine oil (oil helps cool the shock by transferring heat to the strut body).
It doesn't matter which engine oil you use.
10. Install in reverse order. Tighten the threaded collar with the required force. Make sure the end of the coil spring is flush with the rubber ring flange and the spring retainer. Tighten the shock absorber nut to the required torque.
11. Install suspension strut or shock assembly (see Section Removal and installation of assembly of a rack of a forward suspension bracket).