The BMW 3 Series uses a self-adjusting clutch (SAC - Self Adjusting Clutch). When removing and installing this clutch, it is imperative to press the pressure plate with a special BMW tool. A similar tool is also available from KLANN. In addition, a special BMW or KLANN centering rod is required to install the driven disc. This describes the workflow using the BMW tool. If the KLANN tool is used, its description must be followed.
Withdrawal
1. Remove manual transmission, refer to Section Removal and installation of manual transmission.
2. Fix the engine flywheel at the ring gear with a screwdriver and a rod or a special BMW tool -1-. There is a similar KLANN KL-0110 tool.
The special tool BMW 21 2 160 or KLANN KL-0500-10 may only be installed at the points shown in the illustration, otherwise the clutch may be damaged.
The illustration shows the engagement with the centering rod inserted. The instrument has not yet been inserted.
3. Insert precompressor, refer to illustration. Tighten the screw -1- and check the reliability of its position.
4. Screw in the screw -2- so that the springs -3- are compressed to the stop. Loosen the clutch basket mounting bolts sequentially by 1 - 1.5 turns so as to unload the pressure plate.
If all the bolts are loosened at once, the springs and pins of the clutch basket and flywheel may be damaged due to misalignment.
5. Finally, completely remove all bolts.
6. Remove the clutch basket and driven disc.
Do not drop the basket and driven disc when removing, otherwise the clutch may malfunction after assembly.
7. Wipe the flywheel.
Examination
1. Check for burrs on the flywheel. If present, the flywheel must be replaced. After each removal it is necessary to install new special bolts. Tighten the flywheel-to-crankshaft bolts crosswise to the specifications.
2. Check the ease of rotation of the guide bearing (deep groove ball bearing). Otherwise, remove the bearing with a puller, for example, KLANN KL-0043-31 and press in the new bearing to the stop with a hammer and a brass rod until it stops.
3. Remove the clutch release bearing from the support pipe on the manual transmission and check, refer to Section Removal and installation of the clutch release bearing.
4. Check the adjacent surface of the pressure plate for cracks, overheating and wear. A pressure plate having a deflection of up to 0.3 mm inward can be installed. Checking is done with a ruler and a probe.
5. Clean the pressure plate and flywheel with micrometer sandpaper.
6. Check the clutch basket springs for damage.
7. Replace oily or mechanically damaged disk.
8. Measure the thickness of the friction linings of the driven disk with a caliper. To do this, measure the distance between the friction surface and the rivet heads -A-.
The distance must be measured at the locking head -A- and not at the rivet head -B-. The distance must remain at least 1.0 mm. Otherwise, the disk must be replaced.
Installation
When installing new parts, the corrosion protection varnish should only be removed from the friction surfaces of the pressure plate and flywheel. Do not immerse the clutch basket in solvent or blow it out with compressed air, otherwise the function of the clutch adjustment mechanism is not guaranteed.
Installing a used clutch basket
1. Move the adjusting ring back. To do this, place the clutch basket together with the preload tool on a clean pad. Fix the adjusting ring with a screwdriver at one of the grooves -1-
2. Loosen the screw -2- of the preload tool until the adjusting ring can be turned with a screwdriver.
3. Turn the adjusting ring at the pressure elements -1- to the left as far as it will go with a screwdriver.
4. Insert the retainer -3- into the groove. Thus, the adjusting ring is fixed.
5. Screw in the screw of the tension tool so that the diaphragm spring in the basket is pressed against the stop.
6. Insert the clutch disc into the flywheel.
7. Center the clutch disc in the flywheel using tool -1-, eg BMW 21 2 142 or KLANN KL-0500.
8. Place the clutch basket on the appropriate pins. Tighten the clutch basket bolts sequentially 1 to 1.5 turns until it is secured. Make sure that when tightening the bolts, the clutch basket sits evenly on the flywheel. The tightening torque depends on the strength class of the bolts, which is stamped on the bolt head. Please refer to Specifications.
9. Loosen the screw with the preload tool until the spring in the basket is completely unloaded. Loosen screw -1- and remove tool.
10. Take out the centering device with a bolt -2- from a conducted disk. To do this, screw in the bolt and pull it.
Installing a new clutch basket
11. Insert the driven disk into the flywheel.
12. Center the clutch disc in the flywheel with tool -1- for pilot bearing in crankshaft, eg BMW tool 21 2 142 or KLANN KL-0500.
13. Put the clutch basket on the appropriate pins. Tighten the clutch basket mounting bolts 1 to 1.5 turns sequentially so that the disc is secured. Make sure that when tightening the bolts, the clutch basket is drawn evenly into the flywheel. The tightening torque depends on the strength class of the bolts, which is stamped on the bolt head, refer to Specifications.
The locking element -1- may only be removed when the clutch basket is secured. Turn out the locking element with a socket wrench -2- by 14 mm by turning it clockwise.
When the locking element is turned out, the diaphragm spring may make a characteristic noise, which should not be paid attention to.
14. Pull the centering tool out of the driven disk with a bolt. To do this, screw in the bolt and pull it.
15. Remove the centering tool from the flywheel.
16. Lubricate the grooves of the splined connection of the input shaft of the manual transmission with a thin layer of grease "ESSO UNIREX".
Do not apply too much grease, otherwise it may get on the friction surfaces of the clutch and cause clutch failure. The required amount of grease is approximately the size of a grain of rice. Then move the driven disk on the manual transmission shaft in different directions so that the hub easily walks along the shaft. Remove excess grease.
17. Install manual transmission, refer to Section Removal and installation of manual transmission.