Withdrawal
Remove gearbox (see section «Removal and installation of a transmission»).
Gradually loosen the drive disc mounting bolts by 1-1½ turns each time until it is unloaded.
Caution: If the bolts are loosened immediately, the diaphragm spring may be defective.
To prevent the flywheel from turning when loosening the bolts, block the flywheel with a screwdriver or a rod.
Finally, completely unscrew the bolts.
Remove the drive and driven discs.
Attention: Protect the drive and driven discs from impacts, as the result of damage may be difficult disengagement of the clutch or jerking of the clutch after it has been installed.
Wipe the flywheel with a cloth soaked in gasoline.
Examination
Check the drive disc for scratches and burnt spots.
Check the integrity of the diaphragm spring (arrow).
Check the spring connections of the driving disk and the cover for cracks and the reliability of the fastening of the rivet connections. Replace clutch with damaged or unreliable rivet connections.
Check the working surface of the drive disc for cracks, burnt spots and wear. The drive discs, which are concave up to 0.3 mm inward, can still be reinstalled. Checking is carried out using a ruler and a set of probes.
Check the flywheel for scratches and burnt spots.
Treat the drive disc and flywheel with very fine sandpaper.
Oily and mechanically damaged drive discs must be replaced.
Measure the thickness of the drive disc linings with a caliper. The minimum allowable thickness is 7.5 mm, otherwise the disc must be replaced. The drive disk is also replaced in the presence of burnouts.
Check spring windows, torsion springs and hub for signs of wear. With a compound flywheel, the driven disk has a rigid structure without dampers. Torsion dampers in this case are installed in the flywheel.
Remove the release bearing from the transmission front cover and check (see section «Removal and installation of release bearing»).
At the service station, you can check the runout of the driven disk. Lateral runout should not exceed 0.5 mm.
Attention: This cranking must be carried out if, when reinstalling the previous driven disk, and before that, there were difficulties in releasing the clutch.
Check the ease of movement of the ball bearing in the groove of the crankshaft. If necessary, remove the bearing with a puller and replace.
Installation
Before installing a new clutch, remove the anti-corrosion protective coating from it.
Insert the drive and driven discs into the flywheel. Place the clutch drive plate on the appropriate dowel pins. Center the driven disc in the drive disc. For alignment, it is best to use a HAZET shaft or an input shaft from an old gearbox.
When installing the previous drive disk, install it according to the marking. The marking must face towards the gearbox.
Screw in the drive disc mounting bolts.
Tighten the drive plate mounting bolts 1-1½ turns in sequence. Then remove the centering shaft.
Attention: When tightening the bolts, the driving disc must enter the flywheel evenly and freely. Tightening torque class 8.8 (marked on the head of the bolt) 23 nm, class 12.9-30 nm.
Lightly lubricate input shaft keyways of Molykote Longthern 2 gearbox. For compound flywheels, lubricate keyways with Microlube 261.
Install gearbox (see section «Removal and installation of a transmission»).