194000444 - 2110B20 MANUAL GEARBOX (5-6SPEED) WITH DIFFERENTIAL - DISMANTLING AND REASSEMBLY - WASH AND CHECK PARTS - REPLACE SYNCHRONISERS AND INTERNAL CONTROLS IF NECESSARY

Removing ( Refitting ) 1. Fit the manual gearbox and differential (1a) on the overhaul stand (1b) using the tool (1c).
Two mechanics are needed for this operation.
ToolDescriptionFunctionValidity
1871000000Overhaul standManual gearbox overhaul1.82.2
ToolDescriptionFunctionValidity
1871001014SupportPositioning gearbox and differential on overhaul stand2.2
1. Withdraw retaining clip (1a) and remove hydraulic clutch actuator fitting (1b).
1. Unscrew the fitting and disconnect the hydraulic clutch actuator rigid pipe.2. Undo the tabs of bush (2a) and partly withdraw together with rigid pipe (2b).
1. Undo clips (1a), separate bush (1b) from rigid pipe (1c) and remove.
Replace the bush after disassembly.
1. Undo the bolts (1a) and remove clutch hydraulic actuator (1b) complete with o-ring.
1. Undo and remove the reversing light switch.
1. Using a mallet and a pointed tool, remove the intermediate shaft sealing plug.2. Remove the oil deflector from its seat on the gearbox.
The intermediate shaft sealing plug and the oil deflector should always be replaced.
1. Unscrew the bolts fixing the rear cover.2. Use the tool to cut the sealant on the contact surfaces.
ToolDescriptionFunctionValidity
1870718000BladeCut sealant
3. Remove the rear gearbox cover.4. Removet he underlying oil deflectors.
- Engage 3rd or 4th gear.1. To prevent the input shaft turning, position the shaft locking tool.
ToolDescriptionFunctionValidity
1870853000BushMain shaft counter-torque2.2
2. Undo the bolt fixing the intermediate shaft to the bearing.
Always replace the intermediate shaft bolt; its threads are micro-encapsulated.
- Place the gearbox in neutral and turn the transmission through 90°.
- Keep 3rd or 4th gear engaged.- To prevent the input shaft turning, keep the shaft locking tool in position.
ToolDescriptionFunctionValidity
1870853000BushMain shaft counter-torque2.2
1. Unscrew the main and layshaft bolts.
Always replace the shaft bolts.
- Place the gear lever in neutral.1. Undo the selection lever locating bolt.2. Unscrew the bolts securing the gear selection and engagement lever to the gearbox.3. Remove the gear selection and engagement assembly.
- Turn the gear casing assembly through 180°.1. Undo the inner bolts fixing the clutch casing to the gearbox casing.2. Unscrew bolts (2a) and remove bracket (2b) supporting the gear selection and engagement cables.- Turn the gear casing assembly through 180°.3. Undo the outer bolts fixing the clutch casing to the gearbox casing.
1. Secure the base of extractor-fitting tool (1a) to the gear casing using the bolts provided (1b).
ToolDescriptionFunctionValidity
1870844000Extractor/Fitting toolTool for main and layshaft bearings2.2
2. Tighten the threaded rods into the mainshaft and layshaft by at least 5 turns.3. Holding the rods in place with a wrench, tighten nuts (3a) beneath the reaction bracket and undo the nuts alternately to separate the two half-casings (3b).
- Transfer the gear casing to the bench.1. Remove the oil duct from the gearbox casing.2. Remove the gearbox casing magnet.
1. Move back the 1st - 2nd speed selection shaft, prise sliding bush (1a) from its seat and remove selection shaft (1b) from its seat on the gear half-casing.
1. Position tool (1a) retaining the 4th gear and synchroniser to the mainshaft and secure with bolt (1b).
ToolDescriptionFunctionValidity
1870741000BushLocking main/layshaft synchronizers2.2
2. Apply tool (2a) with the extension and strike it using a plastic mallet. With the aid of a second operator, remove the mainshaft assembly (2b), layshaft assembly (2c) and intermediate shaft assembly (2d) from the gear casing.
ToolDescriptionFunctionValidity
1878082000BushLocking main shaft synchronizers/half-casing opening tool2.2
3. Remove the differential assembly.
- Before removing the shaft bearings, measure the height of the casing surface at the bearings.- Rest the gear casing on a reference surface. Support it so that that the output shaft bearing does not rest on the surface to offset the subsequent measurement.1. Use a feeler gauge (1a) to measure distance (b) of the inner bearing race (1c) from the gear casing contact surface (1d). Perform this operation at three different points evenly distributed over the layshaft bearing inner race.- Add the measured values and divide the result by the number of measurements.- This measurement is required in case the bearings are replaced so that the thickness of the new differential case bearing preload shims can be correctly calculated.- If one measurement deviates from the others by 0.08 mm, repeat the measurement because a measurement error has occurred.- Note the measurements and keep them for subsequent use.
1. Remove the mainshaft bearing from the gearbox casing using the tools (1a) and (1b).
ToolDescriptionFunctionValidity
1870007000GripGrip for tool for extracting bearing/fitting main shaft oil seal/fitting differential bearing race
ToolDescriptionFunctionValidity
1860981000ExtractorAdaptor for extracting bearing2.2
1. Remove the layshaft bearing from the gearbox casing using the tools (1a) and (1b).
ToolDescriptionFunctionValidity
1870007000GripGrip for tool for extracting bearing/fitting main shaft oil seal/fitting differential bearing race
ToolDescriptionFunctionValidity
1870629000ExtractorAdaptor for extracting bearing2.2
- Proceed with dismantling the mainshaft following the instructions given below.1. Remove the 3rd and 4th speed drive fork.2. Remove washer (2a), 4th speed drive gear (2b) complete with needle bearing (2c).3. Remove the 4th speed synchronizer ring.4. Withdraw the 3rd and 4th speed sliding sleeve (4a) and recover the underlying springs (4b), balls (4c) and clips (4d).
- Finish dismantling the mainshaft on a press.1. Position both reaction plates (1a) on the press support surface and secure the mainshaft with the two locking and reaction half-rings (1b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
ToolDescriptionFunctionValidity
1870677000Half-ringsPlate for reaction in the press2.2
2. Using the press equipped with removal tool (2a) and insert (2b), remove:- bush (2c).- 3rd and 4th speed synchroniser (2d).- the support ring of upper axial bearing (2e),- 3rd speed synchroniser ring (2f),- upper axial bearing (2g),- lower needle bearing (open) (2h),- 3rd speed drive gear (2i),- upper needle bearing (open) (2l),- lower axial bearing (2m),
Mark the parts removed to indicate their direction and installation direction upon refitting. Pay particular attention to the synchroniser unit to ensure that the round mark on the sleeve is located on the 3rd speed side.
ToolDescriptionFunctionValidity
1875088000Extractor/DriftExtractor2.2
ToolDescriptionFunctionValidity
1870418000InsertInsert for fitting tool2.2
- Keeping the mainshaft in the press, alter the locking and reaction method.1. Remve both locking and reaction half-rings, turn the two support and reaction plates previously positioned on the press surface.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
2. Working with the press equipped with removal tool (2a) and insert (2b), remove the 5th speed drive gear (2c) from the mainshaft (2d).
ToolDescriptionFunctionValidity
1870418000InsertInsert for fitting tool2.2
The 5th speed drive gear should be replaced after removal.
- Proceed with dismantling the intermediate shaft following the instructions given below.- Transfer the intermediate shaft to the press.1. Lock the intermediate shaft in the press using tools (1a) and (1b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
ToolDescriptionFunctionValidity
1846017000Half-ringsHalf-rings for reaction in the press
2. Working using the press and an appropriate drift, strike the shaft surface and remove:-washer (2a),- 1st speed upper bearing (2b),- 1st speed gear (2c),- 1st speed lower bearing (2d),- 1st speed double synchroniser ring (2e),3. Withdraw the 1st and 2nd speed sliding sleeve (3a) and recover the underlying springs (3b), balls (3c) and clips (3d).
- Keeping the intermediate shaft in the press, alter the locking and reaction method.1. Remve both locking and reaction half-rings, turn the two support and reaction plates previously positioned on the press surface.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
2. Working on the press equipped with an appropriate drift for removal, remove:- bush (2a).- washer (2b),- hub for 1st - 2nd speed sliding sleeve (2c),- 1st - 2nd speed double synchroniser (2d),- 2nd speed drive gear (2e),- needle bearing (2f).
Mark the parts removed to indicate the installation position and direction upon refitting. Pay particular attention to the synchronisation unit.
- If it is necessary to replace one or more layshaft components during servicing, further measurements must be carried out to calculate the correct shim (preload) thickness for the different casing bearings so that the correct alignment is maintained between the differential ring gear and the layshaft gear.- Before dismantling the layshaft, take the following measurement.1. Move the layshaft (1a) to the reference surface and measure the height of shaft (1b) from the reference surface to the lower reverse gear washer to the 4th speed surface.
- Proceed with dismantling the layshaft following the instructions given below.- Transfer the layshaft to the press.1. Lock the layshaft in the press using tools (1a) and (1b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
ToolDescriptionFunctionValidity
1870675000Half-ringsHalf-rings for reaction in the press2.2
2. Using the press equipped with removal tool (2a), remove the 4th speed driven gear (2b).
ToolDescriptionFunctionValidity
1875088000Extractor/DriftExtractor2.2
- Keeping the layshaft in the press, alter the locking and reaction method.1. Change both locking and reaction half-rings (1a), turn the two support and reaction plates (1b) previously positioned on the press surface.
ToolDescriptionFunctionValidity
1870677000Half-ringsPlate for reaction in the press2.2
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
2. Working on the press equipped with an appropriate tool (2b) for removal, remove:- 3rd speed driven gear (2b),- 5th speed driven gear (2c),- needle bearing (2d).- 5th speed synchroniser ring (2e),
ToolDescriptionFunctionValidity
1875088000Extractor/DriftExtractor2.2
3. Remove clips (3a), springs (3b) and balls (3c).4. Remove the 5th speed and reverse sliding sleeve from the shaft.
To remove the 3rd speed driven gear, apply a load of at least 11 tons.
The 3rd and 4th speed driven gear is guaranteed for two removals and you should therefore punch the number of removals undergone on the gear. Replace after the second removal.
- Keeping the layshaft in the press, change the locking and reaction method and position so that the reverse washer does not come away.1. Remve both locking and reaction half-rings, turn the two support and reaction plates previously positioned on the press surface.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
2. Working at the press, remove:- bush (2a).- 5th speed and reverse synchroniser (2b),- reverse synchroniser ring (2c),- reverse driven gear (2d),- needle bearings (2e).
Mark the parts removed to indicate their direction and installation direction upon refitting. Pay particular attention on the synchronisation unit to ensure that the double round mark on the sleeve is located on the reverse side.
Refitting ( Removing ) - Proceed with washing and checking the condition of all the components.- Proceed with dismantling the layshaft following the instructions given below.1. Fit the needle bearing (1a), reverse driven gear (1b), reverse synchroniser ring (1c) and 5th speed and reverse driven gear sliding sleeve hub (1d) to the layshaft, positioned to ensure the clips, springs and balls can then be installed.2. Press-fit bush (2c) by means of the press and tools (2a) and (2b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
ToolDescriptionFunctionValidity
1870152000Fitting toolTool for fitting bush/layshaft 3rd speed driven gear2.2
1. Fit the 5th speed and reverse sliding sleeve (1a), clips, springs and balls (1b) in the seat on the sleeve hub, 5th speed synchroniser ring (1c), the bush, needle bearings (1d0 and 5th speed driven gear (1e).2. Press-fit 3rd speed driven gear (2c) by means of the press and tools (2a) and (2b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
ToolDescriptionFunctionValidity
1870152000Fitting toolTool for fitting bush/layshaft 3rd speed driven gear2.2
- Keeping the layshaft in the press, alter the locking and reaction method.1. Using the press equipped with half-plates (1a), press-fit the 4th speed driven gear (1b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
- If it is necessary to replace one or more layshaft components during servicing, further measurements must be carried out to calculate the correct shim (preload) thickness for the different casing bearings so that the correct alignment is maintained between the differential ring gear and the layshaft gear.- Proceed with reassembling the intermediate shaft following the instructions given below.1. Positon the intermediate shaft in a vice with grip covers to prevent damage to the superfinish on the shaft surface. Fit needle bearing (1a), 2nd speed drive gear (1b), 1st and 2nd speed dual synchroniser ring (1c), 1st and 2nd speed synchroniser (1d), washer (1e) and bush (1f).2. Working with the press equipped with half-plates and a general-purpose fitting tool, press-fit the bush.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
- Fit the 1st speed dual synchroniser.- Fit the 1st speed lower bearing.- Fit the 1st speed gear.
Check that the dual synchronizer teeth are properly fitted in the grooves in the gear.
- Fit the 1st speed upper bearing.1. Respecting the fitting order shown in the figure, fit bearing (1a) (outer cage in relation to the rollers) in the upper part of the 1st speed gear and bearing (1b) inner cage in relation to the rollers) into the lower part of the gear.
1. Working with the press equipped with half-plates (1a) and a general-purpose fitting tool, press-fit washer (1b).
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
Check that the synchronizers rotate freely without interference.
- Proceed with reassembling the mainshaft following the instructions given below.- Transfer the mainshaft to the press and use the locking and reaction tools.1. Position the two support and reaction plates on the press surface.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
2. Fit the 5th speed drive gear on the mainshaft.
- Fit the following components on the mainshaft.1. Fit the lower axial bearing.2. Fit the roller bearings.
1. Fit the 3rd speed driven gear (1a),- Fit the upper axial bearing (1b).- The support ring of upper axial bearing (1c),- Fit the 3rd speed synchronizer ring (1d).- Fit the 3rd and 4th speed synchroniser assembly (1e).- Fit the bush (1f)2. Position both reaction plates on the press support surface.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
3. Working on the press, press-fit the sliding sleeve hub.
After press-fitting the hub, check that the 4th speed drive gear and the synchroniser ring turn freely without interference.
1. Working with the press equipped with an appropriate tool (1a) and with the shaft resting on the half-plates (1b), press-fit bush (1c) on the mainshaft.
ToolDescriptionFunctionValidity
1860837000PlatePlate for support in the press
1. Fit the 3rd and 4th speed sleeve (1a), balls, springs and clips (1b), 4th speed synchroniser ring (1c), needle bearing (1d), 4th speed drive gear (1e) and washer (1f).- If it is necessary to replace one or more layshaft components during servicing, further measurements must be carried out to calculate the correct shim (preload) thickness for the different casing bearings so that the correct alignment is maintained between the differential and the layshaft gear.2. Fit tool (2a) on the mainshaft and lock with shaft bolt (2b).
ToolDescriptionFunctionValidity
1870741000BushLocking main/layshaft synchronizers2.2
- This operation is necessary to prevent the synchroniser unit from coming apart.
The synchronisation springs, balls and pads are not supplied individually. If lost, replace the synchroniser assembly.
- Adjust the compensation washers to align the pinion-ring gear when the layshaft has been changed.1. Move the layshaft (1a) with its new components to the reference surface and measure the height of shaft (1b) from the lower reverse gear washer to the 4th speed surface.- This measurement is required to align the differential ring gear with the pinion by means of the preload shims located under the differential case bearings.
- Take more than one measurement and calculate the average value.- Subtract the average height of the new shaft from the average height of the old shaft measured prior to dismantling.1. If the height difference is negative (new shaft shorter than the old shaft), increase the thickness of compensation washer (1a) and decrease the thickness of compensation washer (1b).- If the value is positive (new shaft longer than the old shaft), apply the opposite oversized or undersized washers to those described above.
- Remove the differential case bearings    Op. 2110D26 DIFFERENTIAL INTERNAL CASING BEARINGS - REPLACE WITH DIFFERENTIAL INTERNAL CASING REMOVED- Take the differential case bearing compensation washers.- Use a micrometer to measure the washer thickness.- Apply an oversize or undersize to the compensation washers equal to the difference between the measured values (washers vary by 0.05 mm).- This means that the overall thickness of both compensation washers remains constant because this determines the preload of the differential taper roller bearings.- During adjustment, the thrust washers must be choosen to achieve the minimum possible tolerance.- If they do not display evident wear or damage, the washers may be used for the subsequent adjustment operations.- Refit the differential case bearings    Op. 2110D26 DIFFERENTIAL INTERNAL CASING BEARINGS - REPLACE WITH DIFFERENTIAL INTERNAL CASING REMOVED- Remove the tool positioned on the layshaft.- To facilitate installation, use string to keep the forks aligned in their seats.
ToolDescriptionFunctionValidity
1870741000BushLocking main/layshaft synchronizers2.2
1. With the aid of a second operator, fit the mainshaft (1a), layshaft (1b) and intermediate shaft (1c) assemblies in the clutch housing with their forks.- Settle the intermediate shaft bearing in its seat using a plastic mallet.
1. Fit the half-casing without the bearings and tighten the gear casing external bolts.
- Fit the main and layshaft bearings.1. Fit the tool for installing the main and layshaft bearings in the gear casing.
ToolDescriptionFunctionValidity
1870844000Extractor/Fitting toolTool for main and layshaft bearings2.2
2. Tighten the threaded rods (2a) into the main and layshaft, then adjust nuts (2b) and drive the shafts evenly in their bearings to finish fitting the gear casing in the clutch housing.
The bearing retaining rings must not be removed. If necessary to replace the bearing retaining rings, fit before fitting the bearings into their seats on the gearbox.
- If refitting the old bearings, do not adjust the differential casing bearing compensation washers.If hte bearings are replaced, take the following measurement before refitting both half-casings.1. Use a feeler gauge (1a) to measure distance (1b) of the inner bearing race (1c) from the gear casing contact surface (1d). Perform this operation at three different points evenly distributed over the layshaft bearing inner race.- Add the measured values and divide the result by the number of measurements.- If one measurement deviates from the others by 0.08 mm, repeat the measurement because a measurement error has occurred.
- Subtract the average height of the casing with the new bearing from the average height of the casing with the old bearing measured before disassembly.1. If the height difference is negative (height of casing with new bearing shorter than height of casing with old bearing), increase the thickness of compensation washer (1a) and decrease the thickness of compensation washer (1b).- If the value is positive (height of casing with new bearing higher than height of casing with old bearing), reverse the oversize or undersize described above.
- Remove the differential case bearings    Op. 2110D26 DIFFERENTIAL INTERNAL CASING BEARINGS - REPLACE WITH DIFFERENTIAL INTERNAL CASING REMOVED- Take the differential case bearing compensation washers.- Use a micrometer to measure the washer thickness.- The oversize washers supplied vary by 0.05 mm.- Apply an oversize or undersize to the compensation washers equal to the difference between the measured values.- This means that the overall thickness of both compensation washers remains constant because this determines the preload of the differential taper roller bearings.- During adjustment, the thrust washers must be choosen to achieve the minimum possible tolerance.- If they do not display evident wear or damage, the washers may be used for the subsequent adjustment operations.- Refit the differential case bearings    Op. 2110D26 DIFFERENTIAL INTERNAL CASING BEARINGS - REPLACE WITH DIFFERENTIAL INTERNAL CASING REMOVED- Bring the bearing retaining rings into contact with the half-casing by striking with a plastic mallet.1. Tighten the old main and layshaft bolts temporarily.
- Turn the gear casing assembly through 180°.- Remove the bolts fixing the two half-casings.- Strike the tool equipped with an extension with a mallet to separate the two half-casings.
ToolDescriptionFunctionValidity
1878082000BushLocking main shaft synchronizers/half-casing opening tool2.2
1. Fit the 1st and 2nd speed selection shaft in the half-casing, taking care to ensure that the shaft fits into the opening on the selection fork.
1. Fit the 1st and 2nd speed selection shaft bush.
- Fit the oil duct.- Remove the gearbox casing magnet.1. Apply LOCTITE 5203 sealant over the contact surfaces between the gear selector cover and the gear casing.
The sealant strip must be 1 mm wide.
1. Fit selector cover (1a) and tighten the new selection lever locating bolt (1b).2. Tighten the bolts fixing the gear selector cover to the gearbox.
Whenver the lever locating bolt is removed, a new one must be fitted.
- Tighten the bolts fixing the selector cover to torque.
ComponentFasteningdia  Value (daNm)Validity
Gear selection and engagement assemblyUpper bolts-(gearbox side) 2.52.2
- Check that the selector unit operates correctly by checking the gear engagement and selection movement.
- Fit the differential in its seat on the half-casing.- Check that the bearing retaining rings are flush against the casing.1. Spread a 1 mm strip of LOCTITE 5203 or equivalent over the gear casing surface.
Do not use LOCTITE in area "A" because it could enter the transmission and block the lubrication holes to cause premature failure of the roller bearings.
- Check that the magnet, oil duct, 1st and 2nd speed selection rod and roller bearing are correctly positioned in their seats on the clutch half-casing.- Position the gear casing on the clutch casing, aligning the shafts and forks with the respective holes.- Fit the gear selection and engagement cable mount bracket.1. Tighten the bolts securing the inner gear casing to the gearbox housing to torque.
ComponentFasteningdia  Value (daNm)Validity
Manual gearbox/diff casingInner bolts-2.82.2
1. Position the shaft locking tool on the mainshaft.
ToolDescriptionFunctionValidity
1870853000BushMain shaft counter-torque2.2
- Remove the old main and layshaft bolts.2. Engage the 3rd and 4th speed and tighten the new main and layshaft bolts to torque.
ComponentFasteningdia  Value (daNm)Validity
Manual gearbox/differential main and layshaftsBolt-10.02.2
3. Tighten the intermediate shaft fixing bolts to torque.
ComponentFasteningdia  Value (daNm)Validity
Manual gearbox/differential intermediate shaftBolt-10.02.2
1. Apply LOCTITE 5900 sealant to the contact surfaces between the parts of the gear casing and rear cover that are in contact.
The sealant strip must be 1 mm wide.
When applying the sealant, avoid spreading the area of contact with the underlying oil pipe.
Do not use an excessive amount of LOCTITE ibecause it could enter the transmission and block the lubrication holes to cause premature failure of the roller bearings.
2. Fit new oil deflectors in the main and layshaft bearing seat.3. Fit the rear cover in its seat and tighten the fixing bolts to torque.
ComponentFasteningdia  Value (daNm)Validity
Gearbox rear coverBolt-(gearbox casing side) 2.52.2
- Fit a new oil deflector and a new intermediate shaft sealing plug, taking care not to press it beyond the staking limit.- Fit the reversing light switch.- Check the condition of the clutch hydraulic actuator sealing ring and moisten slightly with transmission fluid.1. Place the hydraulic clutch actuator (1a) in position and secure it tightening the bolts (1b) to the recommended torque.
If a new hydraulic clutch actuator is fitted, remove the device used for locking during transport (red bracket).
ComponentFasteningdia  Value (daNm)Validity
Clutch hydraulic actuatorBolt-(gearbox side) 0.6 - 1.2
- Refit a new bush in its seat on the gear casing until it can be heard to click into place.
The dog on the bush must align with the seat on the gear casing.
- Refit the rigid pipe in its seat and insert into the bush until it can be heard to click into place.
Check the o-ring on the rigid pipe and replace if necessary.
- Connect the rigid pipe to the hydraulic clutch actuator and tighten the fitting to the specified torque.
ComponentFasteningdia  Value (daNm)Validity
Clutch hydraulic actuator rigid pipeConnector-(actuator side)
- Refit the clutch hydraulic actuator fitting and secure with the retaining clip.- Remove the manual gearbox with differential from the rotary stand and support tool.
Two mechanics are needed for this operation.
ToolDescriptionFunctionValidity
1871000000Overhaul standManual gearbox overhaul1.82.2
ToolDescriptionFunctionValidity
1871001014SupportPositioning gearbox and differential on overhaul stand2.2