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

Removing ( Refitting ) 1. Fit the gearbox and differential (1a) on the overhaul stand using the tool (1b).
Two mechanics are needed for this operation.
DescriptionCodeFunction
1bSupport1.871.001.014Support 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.
DescriptionCodeFunction
2Blade1.870.718.000Removing 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.
DescriptionCodeFunction
1stGearbox casing/ clutch casing support1.870.897.700Gearbox 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.
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 front bearing outer races.
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.
DescriptionCodeFunction
1Half plate1.860.837.000Dismantling 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.
DescriptionCodeFunction
2ndReaction pin1.870.899.100Dismantling 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.
DescriptionCodeFunction
1bHalf plate1.860.837.000Dismantling main shaft
DescriptionCodeFunction
1cReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1aExtraction half-rings1.870.899.200Extracting main shaft front bearing
DescriptionCodeFunction
1bExtractor1.870.845.100Extracting 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.
DescriptionCodeFunction
1Half plate1.860.837.000Dismantling 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.
DescriptionCodeFunction
2aReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1eHalf plates1.870.899.400Extracting 5-6th speed sliding sleeve hub
DescriptionCodeFunction
1fReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1eHalf plates1.860.837.000Extracting hub for 1st-2nd speed sliding sleeve
DescriptionCodeFunction
1fReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1aExtraction half-rings1.870.899.600Extracting layshaft front bearing (B)
DescriptionCodeFunction
1bExtractor1.870.845.100Extracting 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.
DescriptionCodeFunction
1Half plates1.870.899.400Dismantling 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.
DescriptionCodeFunction
2aReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1dHalf plates1.860.837.000Extracting hub for 3rd-4th speed sliding sleeve
DescriptionCodeFunction
1eReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1aExtraction half-rings1.870.899.700Extracting spacer on layshaft (C)
DescriptionCodeFunction
1bExtractor1.870.845.100Extracting 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.
DescriptionCodeFunction
2bReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1dHalf plates1.860.837.000Extracting hub for reverse gear sliding sleeve
DescriptionCodeFunction
1eReaction pin1.870.899.100Dismantling 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).
DescriptionCodeFunction
1aExtraction half-rings1.870.899.500Extracting layshaft front bearing (C)
DescriptionCodeFunction
1bExtractor1.870.845.100Extracting 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).
DescriptionCodeFunction
1aGearbox casing/ clutch casing support1.870.897.700Gearbox casing support for determining bearing pre-loading
2. Fit the rear bearing outer race using the drift (2a) and the grip (2b).
DescriptionCodeFunction
2aDrift1.870.898.500Fitting differential rear bearing outer race
DescriptionCodeFunction
2bGrip1.870.898.400Fitting differential rear bearing outer race
Remove the gearbox casing from the support tool.
DescriptionCodeFunction
.Gearbox casing/ clutch casing support1.870.897.700Gearbox 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)