Figure W 3638. Upper Suspension Strut Mount, Models 316i, 318i, 318is
1. Thrust bearing
2. Lug nut M8
3. Washer
4. Self-locking nut M12x1.5
5. Cap
6. O-ring
7. Washer
8. Spring cup
9. Top spring spacer 3mm
10. Damper
11. Protection tube
12. Spring spacer 3mm
13. Bolt
14. Helical spring
Figure W 3639. Upper Suspension Strut Mount, Models 320i, 325i, 325td
1. Thrust bearing
2. Bolt
3. Support washer
4. Lug nut
5. Thrust washer
6. Self-locking nut M14x1.5
7. Protective cap
8. Top spring spacer 3mm
9. Damper
10. Protective tube
12. Bottom spring pad
Attention: Checking the shock absorber, see the relevant subsection.
Springs and shock absorbers on the same axle are replaced only in pairs. In this case, new parts with the same BMW number as on the removed parts must be fitted. For springs, the BMW number is embossed on the end of the spring, on the front of the shock absorbers, under the spring cup.
Withdrawal
Remove shock absorber.
To remove the shock absorber, it is necessary to compress the coil spring. Compress the spring with a special tool.
Attention: Unscrew the shock absorber nut only when the spring is compressed.
Clamp the suspension strut in a vise and press the spring with a suitable clamping device.
Attention: When installing the legs of the tightening device into the coil of the spring, make sure that they securely surround the coils and that the device cannot come off the spring. It is necessary to compress the spring from 3 opposite sides. The helical spring is highly compressed, so use only a powerful tensioning device. Never tighten the spring with wire. Risk of injury!
Attention: Unscrew the fastening nut only when the spring is compressed.
Remove cap.
Loosen the nut with a bent ring wrench, while holding the piston rod from turning.
Remove spacer.
Remove thrust bearing, see illustrations.
Remove the washer, upper spring cup with gasket, and spring.
Caution: If only the spring needs to be replaced, slowly unload it. If only replacement of the shock absorber is required, the spring remains compressed.
Remove protective tube and plastic spring or rubber bellows.
Unscrew the threaded ring and pull out the shock absorber.
Remove old oil from shock absorber cup.
Attention: Only store the shock absorber in a standing position. If the shock absorber is stored with the piston rod retracted in the supine position after the shock absorber is installed on the vehicle, knocking may occur. If necessary, store the shock absorber with the shock absorber extended at room temperature for no more than 24 hours.
Installation
The shock absorber cannot be pulled out separately from the shock absorber tube; when replacing it, the entire tube with the lower spring cup must be replaced.
Assemble the suspension strut according to drawings W 3638 or W 3639 depending on the model. Ensure that the helical spring is properly attached to the surfaces of the upper and lower spring cups.
Tighten the new self-locking nut to 45 Nm while keeping the piston rod from turning.
Put on the cap.
Install shock absorber.