Clutch Disc: Service and Repair
Clutch disc and pressure plate
Special tools:
998 9742 Conversion kit 998 9742 Conversion Kit
999 5112 GEAR SECTOR 999 5112 Gear Sector
999 5662 Compression tool 999 5662 Compression Tool
999 5663 Centering tool 999 5663 Centering Tool
999 7068 Counterhold 999 7068 Counterhold
Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information is always correct.
Removal
Preparatory work
Remove transmission. Transmission, removing, B5254T7, M66 Transmission, Removing
Note! If the clutch must be replaced there is no need to use the counterhold for the automatic adjustment and the compression tool. The clutch screws can then be removed.
Caution! Under no circumstances may a clutch which has been removed in the way described above be reused.
When removing and installing new or existing clutches, the counterhold for automatic adjustment and the compression tool must be used. This procedure is described in the following procedure.
Blocking the flywheel
Use gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector
Marking the mounting points for the compression tool hooks
The compression tool hooks can only be located in a specific position (opposite the rivets for the reinforcement springs for the clutch). Mark these positions using a marker pen. When the counterhold is installed it is difficult to locate the positions exactly.
Installing the counterhold
The three pins on the counterhold lock the automatic adjustment.
Place the counterhold 999 7068 Counterhold 999 7068 Counterhold as shown in the figure.
Ensure that all the three pins (see the illustration) go down into the correct side in front of the hooks for the automatic adjuster.
Press the counterhold's ring against the pressure plate. Pull out the counterhold's springs. Secure the three hooks in the holes on the clutch as shown in the figure.
Installing compression tool
Install the compression tool 999 5662 Compression tool 999 5662 Compression Tool , together with a rebuild kit 998 9742 Conversion kit 998 9742 Conversion Kit , on the clutch.
Align the tool's hooks with the markings that were made before, and make sure that the hooks grip securely in the clutch housing.
Center the compression tool and tighten the screw to light contact against the diaphragm spring. At the same time, check that the hooks on the tool are in position.
Note the position of the handle with slots. Then screw in by not more than two turns.
Remove the clutch and clutch driven plate. The tools can remain in place on the clutch if it is to be reused.
Note! Take care not to trap any fingers when removing the tool.
Checking clutch
Wipe the clutch. Use a dry cloth.
Check carefully for damage through over-heating, cracks, scoring or other damage to the friction surface.
Check that spring is not damaged or broken.
Checking the pressure plate for out-of-true
Wipe the pressure plate friction area clean.
Check any out-of-true carefully. Use a ruler and a feeler gauge. Out-of-true is permitted in one direction only.
Out-of-true must not exceed 0.2 mm. If out-of-true is greater, replace the clutch.
The clutch must be replaced as a complete unit.
Checking the clutch disc
Wipe off the clutch driven plate. Use a dry cloth. The cloth must be free of oil and contaminants.
Check the clutch carefully for signs of wear, damage through overheating, cracking or other damage.
Note! The clutch disc must always be replaced if there are no radial ripples remaining on the friction coating. The clutch disc must also be changed if there is oil or grease on it.
Checking the flywheel
Check that there are no cracks or large scratches on the flywheel.
To replace the flywheel, see Flywheel, B5254T7, M66 Service and Repair
Check radial run-out. Refer to: Flywheel, radial clearance, checking, B5254T7, M66 Component Tests and General Diagnostics
Installation
Note! For tightening torques, see Specifications. [1][2]Clutch, M/T
Installing clutch disc's centering drift
Use centering drift 999 5663 Centering tool 999 5663 Centering Tool , alternatively together with 999 5675 Socket 999 5675 Socket. The drift is modified with conversion kit 998 9742 Conversion kit 998 9742 Conversion Kit.
Remove the cone from the centering tool.
Install the centering tool in the flywheel center as far in as possible.
Use a wrench as a counterhold for the outer section of the centering tool. Tighten the nut so that the expander locks the centering tool in the crankshaft.
Feel that the drift is secured in the crankshaft.
Installing the clutch driven plate
Caution! Turn the side of the clutch disc hub marked "Gearbox side" outward. If the marking on a previously used clutch disc is erased it is clear from the illustration how the clutch disc must be installed.
Install the cone on the centering tool. Tighten the cone (by hand). Secure the clutch driven plate.
Note! Tightening tools must not be used on the cone or damage may be caused to the clutch driven plate.
Installing compression tool on loose clutch
Note! A clutch must never be installed without using a compression tool.
Mark up where the compression tool's hooks are to be positioned, see Blocking flywheel.
Install the counterhold for the clutch's automatic adjustment, see Installing counterhold.
Install the compression tool on the clutch, see Installing compression tool.
Tighten the compression tool until the sun spring has pressed the clutch's pressure plate to free position. A loud click is heard when the clutch's pressure plate "snaps out.
The clutch is now ready for installation with the compression tool and counterhold in position.
Installing the clutch
Note! For tightening torques, see Specifications. [1][2]Clutch, M/T
Install and align the clutch against the guide pins on the flywheel.
Check that the clutch is in contact with the flywheel all around its circumference.
Install and tighten the 6 x M8 screws crosswise.
Removing tools
Loosen the screw on the compression tool and remove it.
Note! Keep fingers away from the three clutch rivets when removing the compression tool. There is a risk of compression damage.
Remove the hooks. Remove the counterhold.
Remove the cone from the centering tool.
Loosen the nut and then tap lightly with a plastic mallet on the centering drift so that its expander releases. Use a plastic mallet so that the threads are not damaged. Remove the centering drift.
Remove the flywheel gear sector. Check the flywheel. See
To install the transmission, see: Transmission, installing, B5254T7, M66 Transmission, Installing