2401012 - 2110B42 5th speed gears of manual gearbox with differential - r+r with gearbox removed

Removing ( Refitting ) 1. Undo the bolts (1a) and remove the rear cover (1b). Engage any gear using the gear selector/engagement lever.1. Undo the bolt fixing the 5th speed selector fork to the main shaft.Engage 5th speed, pressing the selector fork onto the main shaft.

The simultaneous engagement of two gears will cause the gearbox shafts to lock.

2. Remove the staking and loosen the ring nuts for the main and layshafts. Place the selector fork for 5 ^th speed in neutral.

Positioning the selector fork for 5th speed in neutral is necessary to prevent losing the synchronizer rollers.

1. Completely undo the ring nuts for the main and layshafts.2. Remove the 5th speed driven gear.3. Remove the 5th speed synchronizer rollers and springs retaining flange.4. Remove the 5th speed selector fork.5. Remove the 5th speed sliding sleeve.6. Remove the pre-synchronizer mountings.7. Remove the 5th speed sliding sleeve hub.8. Remove the 5th speed synchronizer ring.9. Remove the 5th speed drive gear.10. Remove the needle bearing for the 5th speed drive gear. 11. Remove the 5th speed drive gear bush.

Starting from the month of June 1998, a new selector fork for engaging 5th speed has been adopted on C510-C513 type gearboxes which replaces the selector fork fitted previously. The new selector fork (no. 46549946) should be fitted on gearboxes where it is already used (production from 6/98), but it is interchangeable with the previous selector fork (fitted on gearboxes produced before 6/98). The previous selector fork (which should only be fitted on gearboxes produced before 6/98) is available from the Parts Division until stocks run out.

1. The new selector fork (1a) differs from the previous one (1b) through the different conformation with the two ends (1c) which partly wrap around the hub for the 5th speed synchronizer being longer. Dismantling new 5th speed engagement fork.1. Lock the hose (1a) in a vice, fitting protective plates then, use a brass drift (1b) alternately on the two ends of the selector fork (1c) until it is released from the hub.

take care not to damage the tapered part of the sleeve and the ends of the selector fork with the drift.

Refitting ( Removing ) 1. Fit the 5th speed drive gear bush.2. Fit the needle bearing for the 5th speed drive gear.3. Fit the 5th speed drive gear.4. Fit the 5th speed synchronizer gear.5. Fit the 5th speed sliding sleeve hub.6. Fit the 5th speed sliding sleeve.7. Place the pre-synchronizer mountings back in their housings.8. Fit the 5th speed control fork.9. Fit the 5th speed synchronizer ring spring and roller retaining flange.11. Fit the 5th speed driven gear. 11. Tighten the new ring nuts for the main and layshafts to torque.

	Fastening	Component	Ø	Value(daNm)
11	Ring nut	GEAR SHAFTS	M20	10 - 12.4

12. Tighten the 5th speed selector fork bolt to torque.

	Fastening	Component	Ø	Value(daNm)
12	Bolt	GEARBOX INTERNAL CONTROLS	M6	1.5 - 1.9

Reassembly of new 5th speed selector fork.1. Lock the sleeve in the vice, with protective plates fitted;2. Position the selector fork so that the tapered end is in the same direction as that of the sleeve, resting it against the side of the sleeve with the smaller diameter; fit the selector fork manually, exerting the necessary pressure, until it is completely engaged in the hub.

When the fitting is complete, check that the sleeve can rotate freely inside the selector fork.

Apply sealant to the contact surfaces between the main and layshaft rear bearings retaining plate and the rear cover.

	Type	Component	Name	Qty.
-	Sealant	GEARBOX SEALS/GASKETS	Loctite 573	-

Fit the rear cover and fix it tightening the bolts to torque.

	Fastening	Component	Ø	Value(daNm)
-	Bolt	GEARBOX REAR COVER	M8	2.1 ÷ 2.6