Take off the dynamo-belt cover, loosen the clamping bolt in the dynamo-strap, turn the dynamo in its mounting until the belt is loose, and remove the belt. Remove the cover from the front end of the rear chain - it is held at the front end by a nut to a stud on the primary-chain cover. Lift the ear on the cover off the stud, at the same time pull the cover forward out of the socket in the rear part of the chain-cover. Sometimes this is easier if the bolt holding the rear part of the cover to the mudguard valance is loosened first.

Remove the split cotters from the nut securing the rear driving sprocket and from the nut on the engine-shaft. Loosen the nut on the gearshaft slightly. This nut is usually very tight, and the spanner will need driving round with a hammer or mallet, and the rear brake should be held on firmly while doing so to prevent the sprocket turning.

Next engage top gear and remove the nut from the engine-shaft. This nut will also require to be driven round to start it and the engine-shaft prevented from turning by holding the rear brake on. Both nuts unscrew anti-clockwise. Special spanners are provided in the tool kit for both these nuts, the pegged spanner (closed end) and the " Ring " spanner respectively.

Unscrew the nut right off the engine-shaft with the belt pulley flange and spring. Do not lose the plain washer which is used between the nut and the shoulder of the shaft. Now unscrew and remove the nut from the gearshaft, take off the plain washer behind it. Pull the sprocket off the shaft, and unhook it out of the chain.

Remove the chain cover fixing screws or on later MAC machines take off the chain cover strap assembly from around the edge of the cover. On MOV and MAC machines remove the nut and washer from the stud below the inspection cap and half-way down the face of the cover. On MSS machines remove the single bolt securing the cover to the crankcase and take off the left-hand footrest and footrest square bar. Pull the outer half of the cover away from the inner part, being careful when separating them not to damage the joint-packing. A distance tube will be found between the two halves. This fits over the edges of the covers around the holes, through which the fixing stud or bolt passes. The purpose of the distance tube is to prevent oil leaking out, and to prevent the cover being crushed in when the fixing nut or bolt is tightened.

The sliding member or shock absorber clutch may now be pulled out off the engine shaft, but the sprocket and chain cannot be removed on account of the chain being of the " endless " type, this making it necessary to take off at the same time the chain wheel from the gearbox.

Remove the small grub screw and the locking plate from the flange of the sleeve-gear nut on the clutch (only on MAC and MSS Models after 1940). It will be seen that the nut has four holes drilled in the flange and the peg-spanner is used to turn the nut. (see Fig. 38 on page 76). Again it will almost certainly be necessary to start the nut (anti-clockwise) by driving round the spanner. Remove the nut and pull off the engine sprocket and whole of the clutch with the chain. To start the clutch out of position it may be necessary to lever the back plate away from the face of the gearbox. Be careful when the clutch is removed not to lose the three small thrust pins from the back plate.

After re-assembling note that the clutch will need re-adjustment. See page 70.