Cluch Replacement
Special Tools:1426, 1801, 4090, 5101, 5207 centering drifts 2484, 2824, 5111, 5113, 5203
Clutch Inspection
To avoid unnecessarily replacing a clutch, check first adjustment of clutch control mechanism.
Clutch Removing
1. Remove gearbox.
2. Install centering drift. (Safety precaution.) Slacken pressure plate mounting bolts crosswise a few turns at a time to avoid warping plate.
3. Remove pressure plate and driven plate.
Check Pilot Bearing
1. Pull out bearing with tool P/N 4090.
2. Clean and sparingly grease bearing. Check that bearing turns easily. Replace if worn.
3. Install bearing. Use special drift P/N 1426, 1801 + 5101 or 5207. Tap in bearing until it bottoms in crankshaft.
Check Pressure Plate and Flywheel
Check for overheating, cracks, scores or other damage to friction surface. Pressure plates cannot be disassembled but must be replaced as a complete unit.
- Blue Spots. Replace pressure plate and flywheel if both have blue spots. If only the pressure plate has blue spots it is not necessary to replace the complete clutch. Images above illustrate fully serviceable pressure plates.
- Scoring. Score marks up to 1 mm (0.040 in) deep are acceptable.
- Warpage. Friction surface warpage up to 0.2 mm (0.008 in), measured with straight edge and feeler gauge, is acceptable.
- Radial cracks. Replace pressure plate. Radial cracks often occur in conjunction with excessive warpage of pressure plate. Images above show pressure plates which should not be used. Radial cracks of the type shown are caused by high temperatures, approx. 800-900 °C (1472-1652 °F)which are usually the result of excessive slipping.
NOTE: This also applies to flywheel surfaces.
Check Warpage Of Pressure Plate
Place a straight edge diagonally across the working surface and measure the clearance "A" between the inner edge of the pressure plate and the straight edge, the clearance must not exceed 0.2 mm (0.008 in).
There must be no clearance whatsoever between the straight edge and the outer edge. Check at several points.
Check wear of diaphragm springs.
Inspect Diaphragm Spring Carefully. If the diaphragm spring is cracked or damaged, the pressure plate must be replaced.
Check Release Bearing
Remove release bearing from clutch fork. Turn it a few times under light pressure so that the balls rotate against the races. The bearing should turn easily without binding at any point.
NOTE: From mid-1984 on, all models are equipped with constant-spin type release bearings.
Lubrication Application
Apply a thin layer of grease to the component with a hard brush. Do not use too much grease.
Check and grease input shaft splines with heat resistant grease. (P/N 1161033-4). Apply with a stiff brush.
Check that release bearing slides easily on transmission guide sleeve. Clean sleeve and grease with PIN 1161033-4.
NOTE:
^ Whenever clutch repairs are performed, to ensure smooth operation of the release bearing and clutch disc, it is important that the splines on the shaft and the guide sleeve for the release bearing be lubricated with heat-resistant grease, P/N 1161033-4.
^ The grease used must be able to resist the high temperatures which can arise in the bellhousing, and must not carbonize.
^ Greases such as graphite grease, molybdenum sulphide grease, or "never-seize" grease carbonize and consequently must not be used.
Install Bearing And Fork
Make sure that the spring is pressed over the pivot ball as illustrated. On B 27/28, lubricate the pivot ball with grease P/N 1161033-4. Make sure that the spring is located correctly on the pivot ball (not in the groove).
CAUTION: Keep linings free from oil. Oil can cause grabbing.
Clutch Installing
Make sure that flywheel and pressure plate are free from grease before installing clutch. Use a degreasing agent and dry with a clean rag.
Install driven plate and pressure plate, with driven plate hub outwards away from flywheel.
Install centering drift to align clutch. Install bolts and tighten crosswise a few turns at a time to avoid wrapage.