MANUAL GEARBOX ML5C

2.0 16V JTD, 2.2 16V JTD

INTRODUCTION

The gearbox is transverse type with 5 forward speeds plus reverse.

• 1 Identification plate
• 2 oil filler plug
• 3 oil drain plug

The following diagram shows a cross section through the gearbox.

• 1 Main shaft
• 2 guide pipe
• 4 gearbox casing
• 5 main shaft clearance adjustment
• 6 5^th speed drive gear
• 7 layshaft
• 9 planet gears
• 10 worm screw (speedometer)
• 11 gearbox speed outlet gear
• 12 differential gears
• 13 differential housing
• 14 ring gear
• 15 differential fastening plate
• 16 1^st and 2^nd speed synchroniser
• 17 2^nd speed driven gear
• 18 3^rd speed driven gear
• 19 3^rd and 4^th speed synchroniser
• 20 4^th speed driven gear
• 21 2^nd speed driven gear
• 22 5^th speed synchroniser
• 3 clutch casing
• 8 1^st speed driven gear

The ML5C gearbox can be broken down into 4 different assemblies

• 1 panel cover
• 2 gearbox gear casing
• 3 clutch casing
• 4 differential housing

DESCRIPTION OF COMPONENTS

Main shaft

The main shaft consists of:

• 1 < SUP > st < /SUP >, 2 < SUP > nd < /SUP >, 3 < SUP > rd < /SUP >, 4 < SUP > th < /SUP > speed gears and reverse made out of one part,
• 5 < SUP > th < /SUP > speed gear fitted with its associated synchroniser.

The main shaft is supported by two taper roller bearings.

The coaxial clutch control device is fitted to the end of the main shaft.

Lay shaft

The lay shaft consists of:

• 1 < SUP > st < /SUP >, 2 < SUP > nd < /SUP >, 3 < SUP > rd < /SUP >, 4 < SUP > th < /SUP > and 5 < SUP > th < /SUP > speed gears are fitted on the shaft,

The layshaft is mounted on:

• a roller bearing on the pinion side
• a ball bearing on the cover side.

Synchronizers

The synchronisers are Borg Warner type with built-in balls.

1^st and 2^nd speed synchroniser

The 1^st and 2^nd sychroniser is double-cone type. Double-cone technology allows fast, effective synchronisation. The integrated system allows effective synchroniser neutrality with the synchroniser at rest (neutral position).

• 1 Control sleeve
• 2 ball
• 3 external synchroniser crown
• 4 twin cone
• 5 internal synchroniser crown
• 6 synchronizer hub
• 7 driven pinion

3^rd and 4^th speed synchroniser

The 3^rd and 4^th speed synchroniser is single cone type.

• 1 Control sleeve
• 2 ball
• 3 piston
• 4 piston spring
• 5 synchroniser crown
• 6 synchronizer hub

5^th speed synchroniser

The 5^th speed synchroniser is single cone type. It is located on the mainshaft to reduce gearbox noise.

Precautions to be followed when refitting the synchronisers.

When refitting the 1^rd and 2^th speed synchroniser, ensure the components are fitted axially in relation to the shaft and the synchoniser components are positioned at an angle:

• Fit from the hub toward the sleeve,
• fit the pistons in their housings so that the notch on the piston is opposite the outer synchroniser crownwheel,
• fit the outer sleeve so that the chamfer on the sleeve is aligned with the notch on the piston.

• 1 chamfer on sleeve
• 2 notch on piston

When refitting the 3^rd and 4^th speed synchroniser, ensure the components are fitted axially in relation to the shaft and the synchoniser components are positioned at an angle:

• Fit from the hub toward the sleeve,
• fit the outer sleeve so that the chamfer on the sleeve is aligned with the notch on the piston.

• 1 chamfer on sleeve
• 2 notch on piston

Reverse brake

This device allows main shaft rotation speed to be reduced quickly to ensure correct reverse engagement.

Operating principle

• A - 5^th speed engagement fork
• B - 5^th speed engagement control shaft
• C - reverse engagement pinion
• D - reverse engagement fork
• E - 5^th speed synchroniser

Differential

The following figure shows the differential assembly

• 1 differential housing
• 2 ring gear
• 3 retaining bolt plate
• 4 differential gears
• 5 shims
• 6 planet gears

Gear selection control

The gear selection mechanism consists of a preassembled modular unit.

To improve gear engagement, the 1^st and 2^nd gear engagement shaft is fitted on ball bearings.

Gear selection is controlled by cables. The selection lever is fitted with a damping mass that reduces vibrations transmitted from the gearbox to the cables.

• 1 damping mass
• 2 reverse engagement lock plate
• 3 1^st and 2^nd speed engagement fork
• 4 3^rd and 4^th speed engagement fork
• A - 5^th speed engagement fork
• 6 reverse engagement fork

The gear selection linkage includes a mechanism that prevents shifting directly from 5^th speed to reverse.

• A - spring
• B - reverse engagement lock plate
• C - selection/gear plate
• D - fixed detent

During selection for engagement of 5^th speed, the selection plate moves left and turns the locking plate about its centre line.

When the 5^th speed is engaged, the selection plate turns about itself to release the locking plate, which returns to its original position.

If an attempt is made to engage reverse directly, from a state of 5^th speed engaged, the selection plate moves toward the locking plate which in turn locks against the fixed detent.