Removal of Top Cover.

The cover, which carries the positive stop gear operating mechanism is held to the housing by ten 2 B.A. nuts and is located by two dowels. Set the gears in neutral, remove all nuts and lift off the cover. Preserve the dowels which may come off with the cover, or remain on the studs.

It is unlikely that the mechanism in the cover will ever require attention and it is not proposed to give details of stripping it down. It is best left alone, but if the cam plate is separated from the ratchet on which it is fitted it must be put back in the same relation to it. Failure to do so would completely derange the gear operation. If it has to be taken off be sure to mark both plate and ratchet for refitting.

Removal of Clutch Bell.

Move the selector forks to engage two gears at once and thus hold the shafts from turning. Bend back the tab washer from the lock-ring. Unscrew the lock-ring with spanner LET780 (Fig. 12) and remove it and the tabwasher. Pull the clutch bell forward off the splines.

Removal of Selector Fork Rods and Forks.

The selector forks rods are screwed into the front wall of the gearbox, and can be drawn out to the rear after taking off the locknuts above the front cover, and screwing them out to the rear. Removal of the fork rod: frees the forks which will lift out.

Removal of Gears and Shafts.

Both primary and secondary gear shafts can be withdrawn with the gears fitted to them as follows. Take off the nuts holding the front cover to the gearbox and heat the rear of the casting around the ballrace housings to free the races. If using a gas flame be most careful not to localise the heat by concentrating it at one point. Aim at heating up the whole area around the bearings. Do not overheat the metal. When hot tap the gears and shafts forward and draw them out with the front cover. The speedometer drive spindle will wind out of place if the secondary shaft is turned. To remove the shafts and bearings from the front cover, heat it and jarr the bearings out of the housings. Preserve the oil seal collar from the rear end of the secondary shaft.

Removal of Gears from Shafts and Refitting.

The primary gear shaft carries a splined gear at each end. These must be pressed off the splines to permit removal of the floating third and fourth speed gears. Note that the splined gears are undercut on one side and have slight shoulders at the other. They must be refitted with the undercut sides facing the floating gears and are pressed right up to the shoulders on the shaft. The smaller of them is at the front (clutch) end of the shaft. The floating gears fit so that their dogs face the fixed dogs on the shaft and the small gear is rearward of the other.

On the secondary shaft there are two floating gears fitted at the extremities of the shaft with a double gear between them. Removal of the ballraces from the shaft ends will allow them to be taken off and the double gear will come away after.

Note when refitting that the larger of the secondary shaft floating gear is at the front (clutch) end, and that the double gear must be fitted with the smaller end at the front.

The Gearbox Oil Seals.

A cork washer is used behind the primary shaft rear end bearing, and if the bearing is removed always fit a new cork washer into the housing, and centralise it carefully after refitting the bearing. There are oil seals at the front end of the primary gear shaft behind the clutch bell, and at the rear of the secondary shaft.

The former can be renewed by using a special tool (Fig. 19). It is not listed as a Service Tool as it can be so easily turned from mild steel bar of suitable size to the dimensions given in the sketch. The secondary shaft oil seal is fitted by means of Service Tool LET786 with the appropriate collar (Fig. 14).

The secondary shaft oil seal should not be fitted until after the ballraces have been inserted into their housings. See next section.