Introduction - MANUAL GEARBOX AND DIFFERENTIAL

The structure of the C514 gearbox used on petrol versions consists of:

a gearbox casing which contains and supports the main and layshafts, rods and gear selector forks and the gear selector and engagement device.

- a rear cover which contains the 5^th speed gears and the rear bearing retaining plate for the main and layshafts

a bell housing which contains the clutch, the thrust bearing and the control linkage. This housing is modified to support the selector unit on versions with a Selespeed electrohydraulic actuator.

Main shaft

The main shaft consists of:

1^st, 2^nd speed and Reverse gears fitted directly on the shaft

3^rd, 4^th and 5^th speed gears fitted on the shaft.

The main shaft is supporte by a front roller bearing and a rear ball bearing.

Layshaft

The layshaft consists of 1^st, 2^nd, 3^rd, 4^th and 5^th speed gears fitted on the shaft.

The layshaft is supported on:

a front conical roller bearing

a rear ball bearing

Gears

The gears are the following type:

helical toothed for the forward speeds

straight toothed for reverse.

Synchronizers

The synchronizers for the forward speeds are the Borg-Warner type.

The arrangement for the synchronizers is the split type because the synchronizers for the 1^st and 2^nd speeds are fitted on the layshaft, whilst those for the 3^rd, 4^th and 5^th speeds are on the main shaft.

This solution reduces gearbox noise in neutral from the moment 3 of the 5 pairs of gears are not driven.

In addition, the engagement and synchronization loads are reduced as a result of the corresponding reduction in the inert masses rotating downstream of the crankshaft.

Differential

On the C.514 gearbox the differential unit is located at the rear of the gearbox casing.

It consists of:

a crown wheel and pinion reduction

a differential housing constructed in a single piece which includes the planet and satellite gears.

The differential is supported by two conical roller bearings.

The planet gears have a splined profile with which the two couplings connected to the two driveshafts which transmit the powr to the wheels.

The drive gear for the speedometer is fitted on the outside of the differential housing.

1, Thrust bearing

2, Main shaft

3, Satellite gears

4, Planet gears

5, Ring gear

6, 1^st speed driven gear.

7, 2^nd speed driven gear.

8, Gearbox casing

9, 3^rd speed driven gear

10, 4^th speed driven gear

11, Rear bearing retaining plate

12, 5^th speed driven gear.

13, Layshaft

14, Rear cover

5^th speed drive gear

16, Bell housing