2110B34 MANUAL GEARBOX (6 SPEED) WITH DIFFERENTIAL - DISMANTLING AND REASSEMBLY - WASH, CHECK COMPONENTS, REPLACE SYNCHRONIZERS AND INTERNAL CONTROLS - Alfa - 159 - eLearn

939010735 - 2110B34 MANUAL GEARBOX (6 SPEED) WITH DIFFERENTIAL - DISMANTLING AND REASSEMBLY - WASH, CHECK COMPONENTS, REPLACE SYNCHRONIZERS AND INTERNAL CONTROLS

) 1. Fit the gearbox and differential (1a) on the overhaul stand using the tool (1b).

Two mechanics are needed for this operation.

	Description	Code	Function
1b	Support	1.871.001.014	Support for gearbox on overhaul stand

1. Undo the bolts (1a), extract the retaining clip (1b) and remove the coaxial clutch cylinder (1c) complete with oil pipe.2. Extract the hydraulic clutch fluid duct from the lower part of the gearbox.3. Undo the inner bolt (3a) fixing the clutch casing (3b) to the gearbox casing.

Rotate the gearbox casing through 180° on the overhaul stand.1. Undo the outer bolts fixing the clutch casing to the gearbox casing.2. Separate the gearbox casing from the clutch casing cutting the sealant using the special tool.

	Description	Code	Function
2	Blade	1.870.718.000	Removing gearbox casing-clutch casing sealant

3. Remove the gearbox casing (3a) from the clutch casing (3b).

1. Remove the mainshaft assemblies (A) (1a) and the first layshaft (B) (1b) complete with the control forks for 1st- 2stand 5th- 6thspeed.

Keep the assemblies joined until they are resting on the workbench.

To allow quick identification, each shaft is given a corresponding letter: main shaft (A), first layshaft (B) and second layshaft (C), as shown in the diagram.

1. Lift out the layshaft (C) complete with the control forks for 3rd- 4thspeed and reverse.2. Remove the differential assembly.

1. Take the gearbox casing support tool (1a) and take pins (1b) marked with the letter (A) corresponding to the letters (A) on the plate (1c).

The identification letters for the position of the pins are on the plate for the support tool; position (A) should be used for the gearbox casing support, positions (B) and (C) should be used for the clutch casing support.

	Description	Code	Function
1st	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

2. Place the gearbox casing (2a) on the support tool positioning as illustrated in the diagram, then secure it using the nuts (2b).

1. Remove the oil duct from the gearbox casing.2. Using pliers, remove the lubrication ducts by the main shaft and the layshafts.

The operation of removing the lubrication ducts destroys them, therefore new parts must be used when refitting.

3. Remove the main shaft and layshaft rear bearing outer race using a USAG 468/2 tool and USAG 468/7 extractor or equivalent tools.

To facilitate recognizing the seats for each of the shafts, the main shaft seat is identified in the diagram by the letter (A), the first layshaft seat by the letter (B) and the second layshaft seat by the letter (C). The extraction operation is the same for all three rear bearing outer races.

4. Remove the main shaft scraper ring (A), the first layshaft scraper ring (B) and the second layshaft scraper ring (C).

1. Remove the magnet collecting any impurities in the transmission fluid from the gearbox casing.2. Remove the main shaft and layshaft front bearing outer race using a USAG 468/2 tool and USAG 468/7 extractor or equivalent tools.

Proceed with dismantling the main shaft (A) following the instructions given below.1. Position the main shaft (A) (1a) in a vice with jaw covers, then unscrew the bolt (1b) retaining the 4thspeed drive gear (1c) and the 6thspeed drive gear (1d).

1. Position the reaction plates on the press support surface and fit the main shaft (A) by the 4thspeed drive gear.

	Description	Code	Function
1	Half plate	1.860.837.000	Dismantling main shaft

2. Working with a press equipped with reaction pin (2a), remove rear bearing (2b), for the 6thspeed drive gear (2c) and th 4thspeed drive gear (2d) and the spacer (2e).

The main shaft (A) should be supported at the bottom during this operation.

	Description	Code	Function
2nd	Reaction pin	1.870.899.100	Dismantling main shaft

1. Remove the 3rddrive gear and 5thspeed drive gear (1a) using a hydraulic press, the plates (1b) and the reaction pin (1c).

The main shaft (A) should be supported at the bottom during this operation.

	Description	Code	Function
1b	Half plate	1.860.837.000	Dismantling main shaft

	Description	Code	Function
1c	Reaction pin	1.870.899.100	Dismantling main shaft

1. Fit the extraction half-rings (1a) in the housing in the extractor (1b); place the tools assembled in this way on the main shaft (A) front bearing and secure them using the nuts (1c).

	Description	Code	Function
1a	Extraction half-rings	1.870.899.200	Extracting main shaft front bearing

	Description	Code	Function
1b	Extractor	1.870.845.100	Extracting main shaft front bearing

2. Position the main shaft (A) complete with extraction tools, on the press support surface then extract the front bearing.

The main shaft (A) should be supported at the bottom during this operation.

Proceed with dismantling the layshaft (B) following the instructions given below.1. From the layshaft (B) remove the fork (1a) controlling 1stand 2ndspeed with the drive fork (1a) for 5thand 6thspeeds.

1. Position the reaction plates on the press support surface and fit the layshaft (B) on the 6thspeed driven gear.

	Description	Code	Function
1	Half plate	1.860.837.000	Dismantling layshaft (B)

2. Working with a press equipped with a reaction pin (2a), remove rear the bearing (2b), the driven gear for 6thspeed (2c) and the needle bearing (2d).

The layshaft (B) should be supported at the bottom during this operation.

	Description	Code	Function
2a	Reaction pin	1.870.899.100	Dismantling main shaft

1. Remove the ring assembly for the synchronizer for 6thspeed.2. Remove the engagement sliding hub for 5th- 6thspeed.3. Remove the pre-synchronizer mountings.

1. Remove the hub retaining circlip for the sliding sleeve for 5th- 6thspeed using appropriate pliers.

When refitting, replace the circlip.

1. Remove the hub for the sliding sleeve for 5th- 6thspeed (1a), the synchronizer ring assembly for 5thspeed (1b) the driven gear for 5thspeed (1c) using a hydraulic press, the plates (1e) and the reaction pin (1f).

	Description	Code	Function
1e	Half plates	1.870.899.400	Extracting 5-6th speed sliding sleeve hub

	Description	Code	Function
1f	Reaction pin	1.870.899.100	Dismantling layshaft (B)

2. Remove the needle bearing.

The layshaft (B) should be supported at the bottom during this operation.

1. Raise the retaining ring (1a), then remove the thrust half-rings (1b) retaining the 2ndspeed driven gear, releasing them from their seats (1c) on the layshaft (B).2. Remove the 2ndspeed driven gear (2a), the needle bearing (2b), the rings (2c) for the 2ndspeed synchronizer.3. Remove the engagement sliding hub for 1st- 2ndspeed.4. Remove the pre-synchronizer mountings.

1. Remove the hub retaining circlip for the sliding sleeve for 1st- 2ndspeed using appropriate pliers.

When refitting, replace the circlip.

1. Remove the hub for the sliding sleeve for 1st- 2ndspeed (1a), the 1st speed synchronizer rings (1b), the upper roller bearing (1c) for the 1st speed driven gear, the 1st speed driven gear (1d) using a hydraulic press and the plates (1e) and the reaction pin (1f).

	Description	Code	Function
1e	Half plates	1.860.837.000	Extracting hub for 1st-2nd speed sliding sleeve

	Description	Code	Function
1f	Reaction pin	1.870.899.100	Dismantling layshaft (B)

2. Remove the lower roller bearing for the 1st speed driven gear.

The layshaft (B) should be supported at the bottom during this operation.

1. Fit the extraction half-rings (1a) in the housing in the extractor (1b); place the tools assembled in this way on the layshaft (B) front bearing and secure them using the nuts (1c).

	Description	Code	Function
1a	Extraction half-rings	1.870.899.600	Extracting layshaft front bearing (B)

	Description	Code	Function
1b	Extractor	1.870.845.100	Extracting layshaft front bearing (B)

2. Position the layshaft (B) complete with extraction tools, on the press support surface then extract the front bearing.

The layshaft (B) should be supported at the bottom during this operation.

Proceed with dismantling the layshaft (C) following the instructions given below.1. Remove from the layshaft (C), the 3rdand 4thspeed drive fork (1a) with the reverse drive fork (1b).

1. Position the reaction plates on the press support surface and fit the layshaft (C) on the 4thspeed driven gear.

	Description	Code	Function
1	Half plates	1.870.899.400	Dismantling layshaft (C)

2. Working with a press equipped with a reaction pin (2a), remove the rear the bearing (2b), the driven gear for 4thspeed (2c) and the needle bearing (2d).

The main shaft (A) should be supported at the bottom during this operation.

	Description	Code	Function
2a	Reaction pin	1.870.899.100	Dismantling layshaft (C)

1. Remove the synchronizer ring assembly for 4thspeed.2. Remove the sliding engagement hub for 3rd- 4thspeed.3. Remove the pre-synchronizer mountings.

1. Remove the hub retaining circlip for the 3rd- 4thspeed sliding sleeve using appropriate pliers.

When refitting, replace the circlip.

1. Remove the hub for the 3rd- 4thspeed sliding sleeve (1a), the 3rdspeed synchronizer ring assembly (1b), the 3rdspeed driven gear (1c) using a hydraulic press, the plates (1d) and the reaction pin (1e).

	Description	Code	Function
1d	Half plates	1.860.837.000	Extracting hub for 3rd-4th speed sliding sleeve

	Description	Code	Function
1e	Reaction pin	1.870.899.100	Dismantling layshaft (C)

2. Remove the needle bearing.

The layshaft (C) should be supported at the bottom during this operation.

1. Insert the extraction half-rings (1a) into their seats on the extractor (1b). Position the resulting tools on the spacer between the 3rd- 4thspeed gears and reverse gears and lock them using the nuts (1c).

	Description	Code	Function
1a	Extraction half-rings	1.870.899.700	Extracting spacer on layshaft (C)

	Description	Code	Function
1b	Extractor	1.870.845.100	Extracting spacer on layshaft (C)

2. Position the layshaft (C) complete with extraction tools, on the press support surface then extract the spacer between the 3rd- 4thspeed gears and reverse gears (2a) using the reaction pin (2b).

The layshaft (C) should be supported at the bottom during this operation.

	Description	Code	Function
2b	Reaction pin	1.870.899.100	Dismantling layshaft (C)

1. Remove the Reverse engagement sliding sleeve.2. Remove the pre-synchronizer mountings.

1. Remove the circlip retaining the Reverse sliding sleeve hub using suitable pliers.

When refitting, replace the circlip.

1. Remove the Reverse sliding sleeve hub (1a), the Reverse synchronizer rings assembly (1b), the Reverse driven gear (1c) using a hydraulic press and the plates (1d) and the reaction pin (1e).

	Description	Code	Function
1d	Half plates	1.860.837.000	Extracting hub for reverse gear sliding sleeve

	Description	Code	Function
1e	Reaction pin	1.870.899.100	Dismantling layshaft (C)

2. Remove the needle bearing.

The layshaft (C) should be supported at the bottom during this operation.

1. Remove the spacer positioned underneath the Reverse driven gear.

1. Fit the extraction half-rings (1a) in the housing in the extractor (1b); place the tools assembled in this way on the layshaft (C) front bearing and secure them using the nuts (1c).

	Description	Code	Function
1a	Extraction half-rings	1.870.899.500	Extracting layshaft front bearing (C)

	Description	Code	Function
1b	Extractor	1.870.845.100	Extracting layshaft front bearing (C)

2. Position the layshaft (C) complete with extraction tools, on the press support surface then extract the front bearing.

The layshaft (C) should be supported at the bottom during this operation.

In the case of repairs to the differential, proceed as described below.1. Remove the differential rear bearing outer race from the gearbox casing using a USAG 468/2 tool and USAG 468/8 extractor or equivalent tools.2. Remove the differential scraper ring underneath.

1. Remove the left driveshaft differential internal shaft seal from the gearbox using a drift.

The operation of removing the seal destroys it, therefore a new seal is required when refitting.

1. Remove the differential front bearing outer race from the clutch casing using a USAG 468/2 tool and USAG 468/8 extractor or equivalent tools.

1. Remove the right driveshaft differential internal shaft seal from the clutch casing using a drift.

The operation of removing the seal destroys it, therefore a new seal is required when refitting.

Refitting ( Removing

) If the following components are being replaced: differential assembly, differential front bearing, differential rear bearing, gearbox casing, the size of the washer for the differential bearing pre-loading must be determined in order to ensure that the alignment between the differential ring gear and the layshaft gears remains correct; proceed as described below.Thoroughly clean the bearing and gearbox casing support surfaces.1. Position the gearbox casing supported by the tool (1a) on the press support surface, fit the scraper ring (1b) removed previously in its seat and the differential rear bearing outer race (1c).

	Description	Code	Function
1a	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

2. Fit the rear bearing outer race using the drift (2a) and the grip (2b).

	Description	Code	Function
2a	Drift	1.870.898.500	Fitting differential rear bearing outer race

	Description	Code	Function
2b	Grip	1.870.898.400	Fitting differential rear bearing outer race

Remove the gearbox casing from the support tool.

	Description	Code	Function
.	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

Remove the clutch casing from the overhaul stand.1. Undo the pins marked with the letter (A) from the support tool (1a) and tighten the pins marked with the letters (B) and (C) in the respective openings (B) and (C); tighten the differential support shim (1b) directly onto the plate (1a).

	Description	Code	Function
1a	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

2. Place the clutch casing (2a) on the support tool positioning as illustrated in the diagram, then secure it using the nut (2b) and the pin (2c).

1. Position the clutch casing supported by the tool (1a) on the press support surface and fit the differential front bearing outer race (1b) in its seat.

	Description	Code	Function
1a	Gearbox casing/ clutch casing support	1.870.897.700	Clutch casing support for determining bearing pre-loading

2. Fit the front bearing outer race using the drift (2a) and the grip (2b).

	Description	Code	Function
2a	Drift	1.870.898.500	Fitting differential rear bearing outer race

	Description	Code	Function
2b	Grip	1.870.898.400	Fitting differential rear bearing outer race

Determine the size of the scraper ring for the differential bearing pre-loading; this procedure should be carried out without the shafts fitted on the gearbox casing.Position the clutch casing on the overhaul stand.1. Position the differential on the clutch casing.2. Fit the gearbox casing (2a) and tighten the fixing bolts (2b) and (2c) to the recommended torque.

	Value daNm	Fastening	Component	dia
2b	(to clutch casing) 2.4	Bolt	MANUAL GEARBOX/DIFF. GEAR CASING	M8

	Value daNm	Fastening	Component	dia
2c	(to clutch casing) 5	Bolt	MANUAL GEARBOX/DIFF. GEAR CASING	M10

1. Fit the lower bush for the tool (1a) through the lower differential half-casing and the upper bush (1b) through the upper half-casing so that the teeth (1c) are matched with the openings (1d); lock the tools using the bolt (1e).

his operation prevents the internal rotation of the planet and satellite gears making them rotate with the differential casing.

	Description	Code	Function
1a	Splined shaft	1.870.898.200	Measuring differential casing rolling torque

2. Fit a torque meter on the tool to measure the rolling torque; rotate the differential through several revolutions and read the measurement taken by the equipment.

	Subject	Value
2	Differential complete with manual gearbox
-	Differential rolling torque	1.5-2.0

If the differential rolling torque figure measured is within the range given in the table then the size of the differential bearing pre-loading shim fitted is correct.If the differential rolling torque figure measured is less than the figure in the table, the differential bearing pre-loading shim has to be removed, following the instructions given previously, a larger shim fitted and the test for determining the differential rolling torque repeated until the figures are correct.If the differential rolling torque figure measured is more than the figure in the table, the differential bearing pre-loading shim has to be removed, following the instructions given previously, a smaller shim fitted and the test for determining the differential rolling torque repeated until the figures are correct.

Once the correct size shim for the differential bearing pre-loading has been determined, undo the fixing bolts and separate the gearbox casing from the clutch casing.After having washed all the components thoroughly and checked them, reassembly the layshaft (C) following the instructions given below.1. Fit the spacer on the layshaft (C).2. Fit the reverse driven gear.3. Fit the needle bearing for the reverse driven gear.4. Fit the Reverse synchronizer ring assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

1. Fit the Reverse sliding sleeve hub (1a) using a hydraulic press and the half-plates (1b) and the fitting tool (1c).

Before fitting the sliding sleeve hub, align the housings for the pre-synchronizer mountings in the hub and the Reverse synchronizer rings.

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting hub for reverse gear sliding sleeve

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting hub for reverse gear sliding sleeve

1. Fit a new Reverse sliding sleeve hub circlip.2. Fit the pre-synchronizer mountings in their housings in the sliding sleeve hub.3. Fit the Reverse engagement sliding sleeve.

1. Fit the spacer between the reversing gears and 3rd- 4thspeed gears (1a) using a hydraulic press, the half plates (1b) and the fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting spacer between reverse gears and 3rd-4th speed gears

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting spacer between reverse gears and 3rd-4th speed gears

1. Fit the 3rdspeed driven gear.2. Fit the needle bearing for the 3rdspeed driven gear.3. Fit the 3rdspeed sychronizer assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

1. Fit the hub for the 3rd- 4thspeed sliding sleeve (1a) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

Before fitting the sliding sleeve hub, align the housings for the pre-synchronizer mountings on the hub and the 3rd speed synchronizer rings.

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting hub for 3rd-4th speed sliding sleeve

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting hub for 3rd-4th speed sliding sleeve

1. Fit a new 3rd-4th speed sliding sleeve hub circlip.2. Fit the pre-synchronizer mountings in their housings in the sliding sleeve hub.3. Fit the 3rd- 4thspeed sliding hub.4. Fit the 4thspeed synchronizer assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

5. Fit the 4thspeed driven gear.6. Fit the needle bearing for the 4thspeed driven gear.

1. Fit a new rear bearing (1a) on the layshaft (C) using a hydraulic press and the half-plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting layshaft rear bearing (C)

	Description	Code	Function
1c	Fitting tool	1.860.824.000	Fitting layshaft rear bearing (C)

1. Rotate the layshaft (C) and place it in the press on the half-plates (1a) supported by the tool (1b).

	Description	Code	Function
1a	Half plates	1.860.837.000	Fitting layshaft front bearing (C)

	Description	Code	Function
1b	Fitting tool	1.860.824.000	Fitting layshaft rear bearing (C)

2. Fit a new front bearing (2a) on the layshaft (C) using the fitting tool (2b).

	Description	Code	Function
2b	Fitting tool	1.870.710.000	Fitting layshaft front bearing (C)

1. Position the Reverse selector fork (1a) on the sliding sleeve (1b).2. Position the 3rd- 4thspeed drive fork (2a) on the reversing drive fork and then on the 3rd- 4thspeed sliding sleeve (2b)

Check that the synchronizers rotate freely without interference.

After having washed all the components thoroughly and checked them, reassembly the layshaft (B) following the instructions given below.1. Fit the 1stspeed lower roller bearing (chamber inside the rollers).2. Fit the 1stspeed driven gear.3. Fit the 1stspeed upper roller bearing (chamber outside the rollers).4. Fit the 1stspeed sychronizer assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

1. Fit the hub for the 1st- 2ndspeed sliding sleeve (1a) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

Before fitting the sliding sleeve hub, align the housings for the pre-synchronizer mountings in the hub and the 1st speed synchronizer rings.

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting hub for 1st-2nd speed sliding sleeve

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting hub for 1st-2nd speed sliding sleeve

1. Fit a new hub retaining ring for the 1st- 2ndspeed sliding sleeve.2. Fit the pre-synchronizer mountings in their housings in the sliding sleeve hub.3. Fit the 1st- 2ndspeed sliding sleeve.4. Fit the 2ndspeed synchronizer assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the sliding sleeve hub.

5. Fit the 2ndspeed driven gear.6. Fit the needle bearing for the 2ndspeed driven gear.

1. Fit the thrust washers (1a), inserting the teeth (1b) in the seats (1c) in the layshaft (B).2. Fit the retaining ring.

1. Fit the needle bearing for the 5thspeed driven gear.2. Fit the 5thspeed driven gear.3. Fit the 5thspeed synchronizer assembly.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

1. Fit the hub for the 5th- 6thspeed sliding sleeve (1a) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

Before fitting the sliding sleeve hub, align the housings for the pre-synchronizer mountings on the hub and the 5th speed synchronizer rings.

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting hub for 5th-6th speed sliding sleeve

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting hub for 5th-6th speed sliding sleeve

2. Fit a new hub circlip for the 5th- 6thspeed sliding sleeve.

1. Fit the presynchronizer pads in their seats on the hub for the 5th- 6thspeed sliding sleeves.2. Fit the 5th- 6thspeed sliding sleeve.3. Fit the 6thspeed synchronizer assembly.4. Fit the 6thspeed driven gear.

Check that the synchronizer teeth are properly fitted in the grooves in the gear.

5. Fit the needle bearing for the 6thspeed driven gear.

1. Fit a new rear bearing (1a) on the layshaft (B) using a hydraulic press and the half-plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting layshaft rear bearing (B)

	Description	Code	Function
1c	Fitting tool	1.860.824.000	Fitting layshaft rear bearing (B)

1. Rotate the layshaft (B) and place it in the press on the half-plates (1a) supported by the tool (1b).

	Description	Code	Function
1a	Half plates	1.860.837.000	Fitting layshaft front bearing (B)

	Description	Code	Function
1b	Fitting tool	1.860.824.000	Fitting layshaft rear bearing (B)

2. Fit a new front bearing (2a) on the layshaft (B) using the fitting tool (2b).

	Description	Code	Function
2b	Fitting tool	1.870.710.000	Fitting layshaft front bearing (B)

1. Position the 1st- 2ndspeed drive fork (1a) on its sliding sleeve (1b).2. Position the 5th- 6thspeed drive fork (2a) on the 1st- 2ndspeed drive fork and then on the 5th- 6thspeed sliding sleeve (2b)

Check that the synchronizers rotate freely without interference.

After having washed all the components thoroughly and checked them, reassembly the main shaft (A) following the instructions given below.1. Fit a new front bearing (1a) on the main shaft (A) using a hydraulic press and the half-plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting main shaft front bearing (A)

	Description	Code	Function
1c	Fitting tool	1.870.899.300	Fitting main shaft front bearing (A)

1. Fit the 3rd- 5thspeed drive gear (1a) on mainshaft (A) using a hydraulic press, plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting 3rd-5th speed drive gear on main shaft (A)

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting 3rd-5th speed drive gear on main shaft (A)

1. Fit the spacer.2. Fit the 4thspeed drive gear (2a) on mainshaft (A) using a hydraulic press, half-plates (2b) and fitting tool (2c).

	Description	Code	Function
2b	Half plates	1.860.837.000	Fitting 4th speed drive gear on main shaft (A)

	Description	Code	Function
2c	Extractor/ Fitting tool	1.870.658.000	Fitting 4th speed drive gear on main shaft (A)

1. Fit the 6thspeed drive gear (1a) on mainshaft (A) using a hydraulic press, plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting 6th speed drive gear on main shaft (A)

	Description	Code	Function
1c	Extractor/ Fitting tool	1.870.658.000	Fitting 6th speed drive gear on main shaft (A)

1. Fit a new rear bearing (1a) on the main shaft (A) using a hydraulic press and the half-plates (1b) and fitting tool (1c).

	Description	Code	Function
1b	Half plates	1.860.837.000	Fitting main shaft rear bearing (A)

	Description	Code	Function
1c	Fitting tool	1.860.824.000	Fitting main shaft rear bearing (A)

1. Place the main shaft (A) in a vice with protective jaws, then tighten the 6thspeed drive gear retaining bolt.

	Value daNm	Fastening	Component	dia
1	4.5	Bolt	CLUTCH MAIN SHAFT SPLINING	M20 X 1.5

Remove the clutch casing complete with differential from the overhaul stand.Clean the clutch casing thoroughly.1. Place the clutch casing on the support tool (1a), positioning it as illustrated in the diagram by the pins (1b) marked with the letters (B) and (C) and tightened in the openings (B) and (C); then secure the clutch casing using the nut (1c) and the pin (1d).

	Description	Code	Function
1a	Gearbox casing/ clutch casing support	1.870.897.700	Clutch casing support for fitting bearing outer races

2. Position the clutch casing supported by the tool on the press support surface and fit the main and layshaft front bearing outer races in the seats.3. Fit the front bearing outer faces using drifts (3a), (3b) and (3c) together with the grip (3d).

To allow faster identification, each shaft is given a corresponding letter: main shaft (A), first layshaft (B) and second layshaft (C), as shown in the diagram.

	Description	Code	Function
3a	Fitting tool	1.870.898.900	Fitting main shaft (A) front bearing outer race on clutch casing

	Description	Code	Function
3b	Fitting tool	1.870.898.700	Fitting layshaft (B) front bearing outer race on clutch casing

	Description	Code	Function
3c	Fitting tool	1.870.898.800	Fitting layshaft (C) front bearing outer race on clutch casing

	Description	Code	Function
3d	Grip	1.870.898.400	Fitting main and layshaft front bearing outer races on clutch casing

Remove the clutch casing complete with differential from the support tool and secure it to the overhaul stand using the bracket.

	Description	Code	Function
.	Support	1.871.001.014	Support for gearbox on overhaul stand

Fit the magnet collecting any impurities in the transmission fluid to the gearbox casing.1. Position in their seat (C) on the clutch casing, the layshaft (C) with the 3rd- 4thspeed and reverse drive forks.

1. Position in their seats (A) and (B) on the clutch casing, mainshaft assembly (A) (1a) and layshaft assembly (B) (1b) complete with the 1st-2ndspeed and 5th- 6thspeed drive forks.

If the one of the following components is being replaced: main shaft, gearbox components, main shaft (A) front bearing, main shaft (A) rear bearing, layshaft (B) assembly, layshaft (C) assembly, layshaft (B) rear bearing, layshaft (C) rear bearing, determine the size of the shims for the main shaft (A), layshaft (B) and layshaft (C) bearing pre-loading following the instructions given below.Clean the gearbox casing, the bearing support surfaces and the surfaces joined with the clutch casing thoroughly.1. Place the gearbox casing (1a) on the support tool (1b) postioning it as illustrated in the diagram by the pins (1c) marked with the letter (A) tightened in the openings (A); then secure the gearbox casing using the nuts (1d).

	Description	Code	Function
1b	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

1. Position the 3 gauges (1a) by the corresponding openings in the rear bearing outer race housings (1b) in the gearbox casing.

There is a letter on each gauge identifying the corresponding reference shaft: the letter (A) identifies the main shaft, the letter (B) identifies layshaft (B) and the letter (C) identifies layshaft (C).

	Description	Code	Function
1a	Gauges	1.870.898.000	Determining main and layshaft bearing pre-loading

1. Fit the reference crossmember (1a) on the gearbox casing and secure it tightening the nuts (1b) to a torque of 2 daNm.

Position the reference crossmember as illustrated in the diagram so that it is correctly aligned with the gauges positioned by the shafts.

	Description	Code	Function
1a	Reference crossmember	1.870.897.800	Determining main and layshaft bearing pre-loading

Determining gearbox casing height (shaft housing)1. Loosen the bolts (1a) located by each gauge; in this way the springs inside the gauges will placethe cylinders (1b) in contact with the bottom surface of the reference crossmember; then check, manually, by rotating the gauges, that the gauge-plate contact is correct. Lock the bolts, loosened previously, in this position.

The height of the gauges in contact with the lower surface of the reference crossmember corresponds to the height of the gearbox casing.Remove the reference crossmember and the gauges from the gearbox casing.1. Fit the three gauges (1a) on the tool plate (1b).

	Description	Code	Function
1a	Gauges	1.870.898.000	Determining main and layshaft bearing pre-loading

	Description	Code	Function
1b	Gauges support	1.870.897.900	Determining main and layshaft bearing pre-loading

1. Match the support for determining the bearing pre-loading complete with gauges (1a) to the mounting plate complete with gauges (1b).

Position the support for determining the bearing pre-loading as illustrated in the diagram so that the references A-A, B-B and C-C are aligned with the shafts.

	Description	Code	Function
1a	Support complete with gauges	1.870.898.100	Determining main and layshaft bearing pre-loading

	Description	Code	Function
1b	Gauges support	1.870.897.900	Determining main and layshaft bearing pre-loading

2. Fasten the support for determining the bearing pre-loading to the plate tightening the special bolts to a torque of 2 daNm.3. Zero the dial gauge pointers with a pre-loading of 3 mm for each gauge.

To zero the dial gauges correctly, rotate the gauges 3 - 4 turns and only proceed with the zeroing in the most negative position shown on the gauge.

Remove the support for determining the bearing pre-loading from the base plate complete with gauges.1. Position the support for determining the bearing pre-loading on the gearbox casing ensuring that pointer A- main shaft A, pointer B-layshaft B and pointer C-layshaft C are correctly matched.2. Fasten the support for determining the bearing pre-loading to the gearbox casing using special bolts.3. Rotate the main and layshafts through thirty revolutions using the tool (3a) and a suitable crank (3b).

	Description	Code	Function
3a	Bush for main shaft counter-torque	1.870.899.000	Determining main and layshaft bearing pre-loading

Measure the differences in relation to the main shaft (A), the layshaft (B) and the layshaft (C) using the three dial gauges.To determine the size of the main shaft (A) scraper ring to be used from the ones available from spares, subtract 0.01-0.06 mm, corresponding to the endfloat of the main shaft (A) bearing from the difference measured.To determine the size of the layshaft (B) and layshaft (C) scraper ring to be used from the ones available from spares, subtract 0.05-0.10 mm, corresponding to the value of the bearing pre-loading.Remove the tool for determining the bearing pre-loading from the gearbox casing.1. Fit the lubrication duct.2. Fit the main shaft (A) scraper ring of the size calculated.3. Fit the main shaft rear bearing outer race (3a) on the gearbox casing supported by the tool (3b) using a hydraulic press, the fitting tool (3c) and the grip (3d).

	Description	Code	Function
3b	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

	Description	Code	Function
3c	Fitting tool	1.870.898.600	Fitting main and layshaft rear bearing outer races

	Description	Code	Function
3d	Grip	1.870.898.400	Fitting main and layshaft rear bearing outer races

Fit the lubrication ducts, the scraper rings of the size calculated and the rear bearing outer races for layshaft (B) and layshaft (C), proceeding as illustrated for the main shaft (A) and using the same equipment.Fit the oil duct in the gearbox casing.Apply the recommended sealant to the entire matching surface between the gearbox casing and the clutch casing.

	Description	Q.ty	Component	Type	Classification
.	Loctite 510	-	GEARBOX COMPONENTS	Sealant	-

Remove the gearbox casing from the support tool.

	Description	Code	Function
.	Gearbox casing/ clutch casing support	1.870.897.700	Gearbox casing support for determining bearing pre-loading

Fit the gearbox casing and secure it to the clutch casing tightening the bolts to the recommended torque.

	Value daNm	Fastening	Component	dia
.	(to clutch casing) 2.4	Bolt	MANUAL GEARBOX/DIFF. GEAR CASING	M8

	Value daNm	Fastening	Component	dia
.	(to clutch casing) 5	Bolt	MANUAL GEARBOX/DIFF. GEAR CASING	M10

1. Fit a new seal (1a) for the left driveshaft side differential internal shaft using the fitting tool (1b).

	Description	Code	Function
1b	Fitting tool	1.870.899.800	Fitting differential seal (left side)

Turn the gearbox on the overhaul stand.1. Fit a new seal (1a) for the right driveshaft side differential internal shaft using the fitting tool (1b).

	Description	Code	Function
1b	Fitting tool	1.870.899.800	Fitting differential seal (right side)

Tighten the inner bolt fixing the clutch casing to the gearbox casing to the recommended torque.

	Value daNm	Fastening	Component	dia
.	(to clutch casing) 5	Bolt	MANUAL GEARBOX/DIFF. GEAR CASING	M10

Position the coaxial clutch cylinder and secure it using the fixing bolts.

	Value daNm	Fastening	Component	dia
.	(clutch casing) 1	Bolt	CLUTCH CONTROL HYDRAULIC ACTUATOR	M6

Insert the hydraulic clutch oil duct through the special opening in the lower part of the gearbox.Lock the hydraulic clutch oil duct on the coaxial cylinder using the retaining clip.Undo the fastenings and remove the gearbox and differential from the tool.

Two mechanics are needed for this operation.

	Description	Code	Function
.	Support	1.871.001.014	Support for gearbox on overhaul stand

Remove the support tool from the overhaul stand and put it down.