31 31 041 Replacing Front Left or Right Spring Strut

31 31 041 Replacing front left or right spring strut (M3)

Special tools required:





Important!
- When replacing shock absorber/spring strut, renew auxiliary damper!

Warning!
Before using the special tool 31 3 340 take care to read through the Owner's Handbook!





All the safety information and instructions contained in the Owner's Handbook must be strictly observed!
Failure to observe these safety precautions and instructions increases the risk of serious physical injury, damage to your health and damage to property and equipment!





Important!
1. Prior to each use, check the special tools for defects, modifications and operational reliability.
2. Damaged/modified special tools must not be used!
3. No changes or modifications may be made to the special tools!
4. These special tools are intended solely for the purpose of tightening and relieving cylindrical and tapered suspension springs.
5. Keep special tools dry, clean and (down to the spindle) free from grease.
6. The use of an impact screwdriver on special tool 31 3 341 is prohibited!
7. Do not compress coil spring to full extent.





Necessary preliminary work:
^ Remove front spring strut.





Removing:
Clamp special tool 31 3 341 in vice.

Fit special tools 31 3 351 from above on special tool 31 3 341 until retaining bolts (1) can be felt and heard to snap into place.

Check seating of special tools 31 3 351 and, if necessary, correct.





Clean coil spring to remove all coarse dirt and mount on special tools 31 3 351.

Turn spring strut until lower end of coil spring (1) points upwards.

Warning!
Danger to life!





The upper and lower coils of the coil spring must be situated entirely in the recess of special tools 31 3 351.

Compress coil spring until stress on piston rod is relieved.





Warning!
Danger to life!
Nut may only be released if:
1. the coil spring has been sufficiently tensioned with special tools 31 3 341 and 31 3 351
2. the upper and lower coils of the coil spring are situated entirely in the recess of special tools 31 3 351

Release nut (1) (grip piston rod in so doing) and remove support bearing (2).

Important!
Risk of contamination!
Ensure conditions of absolute cleanliness when handling the two-part support bearing.








Pull off support disc (1) and auxiliary damper (2) with gaiter (3) from piston rod of shock absorber (4).

Remove shock absorber (4) sideways from coil spring.





Relieve tension on coil spring and remove from special tools 31 3 351.

Installation:

Important!
Risk of mixing up





The lower coil of the coil spring is slightly smaller than the upper coil.





Accommodate coil spring with special tools 31 3 351.

Turn coil spring until lower end of coil spring (1) points upwards.





Warning!
Danger to life!
Do not compress coil spring to full extent.
The upper and lower coils of the coil spring must be situated entirely in the recess of special tools 31 3 351.

Tension coil spring.

Replace spring pad (1).

Important!





Make sure spring pad (1) is correctly seated on shock absorber. Guide (2) must be correctly seated in opening (3) in shock absorber!





Check auxiliary damper and gaiter for damage, replace if necessary.





Important!
Make sure support disc and folding of gaiter are correctly positioned (see graphic).

Insert shock absorber (4) in tensioned coil spring.

Slide auxiliary damper (2) with gaiter (3) onto piston rod.

Attach support disc (1) to piston rod.

Replace spring pad (1).





Important!
Make sure spring pad (1) is correctly seated on support bearing.





Check support bearing (1) for damage, replace if necessary.

Attach support bearing (1) to piston rod.

Coat mounts (2) with Circo Light (sourcing reference: BMW Parts Service).





Note:
Joint plate (1) is correctly seated in support bearing mounts after tension is relieved on coil spring.

Attach joint plate (1) to piston rod.

Replace nut (2) and tighten down (gripping piston rod in so doing).

Tightening torque 31 31 2AZ.

Important!
Upper coil of coil spring must rest positively on support bearing!





Lower end of coil spring (2) must rest on stop of spring pad (1)!

Relieve tension on coil spring.

Check installation position of gaiter (3), correct folds if necessary.





After installation:
^ Carry out wheel alignment check if a spring strut with support bearing was or is installed without centering pin.