Manual - Chapter 2 Clutch

3. Dismantling

  1. Before starting dismantling work check the clutch components for balancing marks; there should be a yellow- or white-painted mark on the cover plate, pressure plate and housing, which should be spaced at 120' to each other. If no marks can be seen, make your own. Using paint or a thick-rubbed felt marker, draw a line across the housing, pressure plate and cover plate so that these three components can be refitted in their original position by aligning their marks. Remember that they represent a significant proportion of the engine's rotating mass and, if unbalanced, may produce severe vibration.
  2. Note also which way round the clutch friction plate is fitted; the longer extended part of the centre boss usually faces towards the gearbox. It is advisable to mark the outer (rearmost) face of the clutch friction plate with paint or a felt marker to ensure that this is not fitted the wrong way round on reassembly.
  3. Slacken the six bolts or screws around the periphery of the cover, then, working in a diagonal sequence, slacken each bolt or screw by one turn at a time to release spring pressure smoothly and evenly. When spring pressure is released, remove the six bolts or screws and their lock washers.
  4. Remove the cover plate, clutch friction plate, pressure plate (checking the balancing marks) and diaphragm spring, noting which way round the latter is fitted. If the cover plate is very tight on its three locating dowels it must be carefully levered away; take care not to let it fly off under spring pressure. The wire ring can be prised out of the housing if desired.
  5. The housing must be locked to prevent rotation while the retaining nut is slackened. On 100 models pass a large wooden rod (a hammer handle or similar) through one of the holes in the housing and lock it against the crankcase webs.
  6. On 75 models obtain a short but thick strip of metal with an 8 mm (0.32 in) hole drilled in one end. Attach this to the housing using one of the cover plate bolts or screws and wedge it against a strongly-reinforced part of the bellhousing so that the housing cannot rotate anticlockwise.
  7. Both of the above methods are an alternative to the use of the BMW service tool number 11 2 800 which is meant to bolt to the housing so that it will lock against the bellhousing wall. The tool would not fit the housing of the machine featured in the accompanying photographs, however, and required some modification. If owners wish to fabricate such a tool the basic dimensions are given in the accompanying illustration (See Fig 2.3); the standard item is constructed of metal strip 6 mm (0.24 in) thick and may need to be shortened to approximately 220 mm (8.66 in) to fit inside the bell
  8. With the housing securely locked, unscrew the retaining nut and withdraw the shouldered spacer behind it. Grasp the housing in both hands and work it backwards and forwards aiong the shaft splines until the O-ring can be reached and removed with a pointed instrument. Withdraw the housing, noting the thrust washer fitted to it (100 models only).
  9. If it is to be renewed, the pushrod pilot bearing can be extracted by cutting a thread on its inside (6 mm/O.24 in dial using a suitable tap and then screwing in a bolt or screw which can be gripped to provide purchase for removal; do not screw the tap or extracting tool in too far as the locking plug (100 models only) may be damaged. Do not disturb the pilot bearing unless necessary.

3.3 Note balancing marks and installed direction of friction plate before dismantling clutch

3.8 Removing O-ring from centre of clutch housing