485588 - 2110B26 MANUAL GEARBOX (6 speed) and differential - Dismantling and reassembly - Washing components - Replacing synchronizers and internal controls, if necessary

Removing ( Refitting ) 1. Release the gearbox and differential (1a) from the hydraulic jack (1b) and from the tool (1c) used for removing-refitting it from the vehicle.
DescriptionCodeFunction
1c Support1.870.644.001Gearbox support bracket whilst overhauling
1. Fit the gearbox and differential (1a) on the overhaul stand using the tool (1b).
Two mechanics are needed for this operation.
DescriptionCodeFunction
1b Support1.871.001.014Gearbox support whilst overhauling
1. Remove the left differential internal driveshaft (1a) using the tools (1b) and (1c).
DescriptionCodeFunction
1b Flange1.847.017.004Extracting left differential internal driveshaft
DescriptionCodeFunction
1c Mallet1.840.206.001Extracting left differential internal driveshaft
1. Undo the bolts (1a) and remove the flanges on the differential (1b) complete with seals.2. Remove the scraper ring.
1. Undo the bolts (1a) and remove the differential internal casing support (1b).2. Remove the differential.3. Remove the differential bearing outer races.4. Remove the magnet.
1. Undo the reverse shaft bolt.2. Undo the bolts (2a) and remove the gearbox casing (2b).
The gearbox casing is sealed to the bellhousing: release the two parts using a wooden or resin hammer.
1. Undo the bolts (1a) and (1b).2. Release the 5-6 th speed control rod from the reverse fork and the 5 th speed selector.3. Release the 5-6th speed fork from the control rod.
1. Simultaneously remove the main shaft, layshaft, reverse shaft and 1st, 2nd, 3rd and 4th speed fork assemblies.
Keep the assemblies joined until they are placed on the workbench.
- Separate the forks from the rods.
1. Undo the bolts (1a) and remove the clutch actuator main shaft cover (1b).
1. Remove the main shaft rear bearing outer race (1a) using tools (1b) and (1c).
DescriptionCodeFunction
1b Extractor/Fitting tool1.870.655.000Extracting main shaft rear bearing outer race
DescriptionCodeFunction
1c Mallet1.840.206.001Extracting main shaft rear bearing outer race
2. Remove the main shaft scraper ring from the gearbox casing.3. Remove the lubrication duct.
1. Remove the layshaft rear bearing outer race (1a) using tools (1b) and (1c).
DescriptionCodeFunction
1b Extractor/Fitting tool1.870.655.000Extracting main shaft rear bearing outer race
DescriptionCodeFunction
1c Mallet1.840.206.001Extracting layshaft rear bearing outer race
2. Remove the layshaft scraper ring.
- Proceed with dismantling the layshaft following the instructions given below.1. Check that the opening between the gear teeth and the synchronizer ring support planes is within the recommended values at three points.
When taking this measurement, keep the sliding sleeve raised using a screwdriver. If the figures do not correspond with the recommended values, the worn synchronizer must be replaced during the reassembly.
1. Remove the rear bearing (1a), the 6 th speed driven gear (1b), using a hydraulic press, the support (1c) and half rings (1d) and a suitable drift (1e).
DescriptionCodeFunction
1c Half-rings support1.846.017.001Extracting 6th speed rear bearing and driven gear
DescriptionCodeFunction
1d Half-rings1.870.676.000Extracting 6th speed rear bearing and driven gear
2. Remove the spacer.
1. Remove the 5th speed driven gear (1a) and the 4th speed driven gear (1b) using a hydraulic press, the half plate (1c) and half rings (1d).
DescriptionCodeFunction
1c Half-rings support1.846.017.001Extracting 4-5th speed driven gear
DescriptionCodeFunction
1d Half-rings1.870.675.000Extracting 4-5th speed driven gear
2. Remove the spacer.
1. Remove the 3rd speed driven gear (1a) and the 2nd speed driven gear (1b) using a hydraulic press and the half plate (1c).
DescriptionCodeFunction
1c Plate1.874.290.000Extracting 3rd-2nd speed driven gear
1. Remove the needle bearing for the 2nd speed driven gear.2. Remove the triple cone synchronizer and 1st and 2 nd speed.3. Remove the engagement sliding sleeve for 1 st speed, 2nd speed and reverse (3a) and the spring/roller (3b).
1. Remove the circlip using suitable pliers.
When refitting, replace the circlip.
1. Remove the hub for the 1st speed, 2nd speed and reverse sliding sleeve (1a), the 1st speed triple cone synchronizer (1b), the 1st speed driven gear (1c), using a hydraulic press and the 1st speed half plate (1d).
DescriptionCodeFunction
1d Half plate1.874.290.000Dismantling layshaft
2. Remove the needle bearing for the 1nd speed driven gear.
1. Remove the circlip using suitable pliers.
When refitting, replace the circlip.
1. Remove the front bearing (1a) using a hydraulic press, a suitable plate (1b), the reaction base (1c) with the outer race (1d) for the bearing in question inside.
DescriptionCodeFunction
1c Reaction base1.870.660.000Dismantling layshaft
- Proceed with dismantling the reverse shaft following the instructions given below.1. Remove the reverse drive gear - reverse synchronizer assembly from the reverse shaft.
1. Remove the circlip using suitable pliers.2. Remove the reverse gear synchronizer.3. Remove the spring (3a) from the reverse drive gear (3b).
1. Remove the O-ring.2. Remove the pin.3. Remove the needle bearing for the reverse drive gear (3a) complete with bush (3b).4. Remove the reverse driven gear.5. Remove the needle bearing for the reverse driven gear.
Refitting ( Removing ) - Proceed with reassembling the reverse shaft following the instructions given below.1. Fit the needle bearing for the reverse drive gear (1a) on the reverse shaft (1b).2. Fit the reverse driven gear.3. Fit the needle bearing for the reverse drive gear complete with bush.4. Fit the pin.5. Fit a new O-Ring.
1. Fit the spring (1a) on the reverse drive gear (1b).2. Fit the reverse gear synchronizer.3. Fit the circlip.
- Fit the reverse drive gear - reverse synchronizer assembly on the reverse shaft.- Proceed with reassembling the main shaft following the instructions given below.
Lubricate the bearings with the recommended oil before refitting them.
DescriptionQty.ComponentTypeClassification
.TUTELA ZC 75 SEMI SYNTH-MANUAL GEARBOX/DIFFERENTIALOilSAE 75W90 - API GL 5
1. Fit the front bearing (1a) using a hydraulic press, a suitable plate (1b), the fitting tool (1c) and the half rings (1d).
DescriptionCodeFunction
1c Extractor/Fitting tool1.870.658.000Fitting front bearing
DescriptionCodeFunction
1d Half-rings1.845.063.000Fitting front bearing
1. Using a feeler gauge, measure the housing for the front bearing circlip to be fitted.
1. Fit a new front bearing circlip.
The size of the circlip is selected from those available as spares depending on the previous measurement of the housing.
2. Fit the needle bearing for the 1st speed driven gear.3. Fit the 1st speed driven gear.4. Fit the 1st speed triple cone synchronizer.
1. Fit the hub for the 1st speed, 2nd speed and reverse sliding sleeve (1a) using a hydraulic press, a suitable plate (1b) and the fitting tool (1c).
DescriptionCodeFunction
1c Extractor/Fitting tool1.870.658.000Reassembling layshaft
1. Fit a new circlip.2. Fit the 1st speed, 2nd speed and reverse sliding sleeve so that the internal references are aligned with the springs.
1. Fit the 1a spring/roller on the hub for the 1st speed, 2nd speed and reverse sliding sleeve.2. Fit the needle bearing for the 2st speed driven gear.
1. Fit the triple cone synchronizer (1a) on the 2nd speed driven gear (1b).2. Fit the assembly constructed as described in the previous stage on the layshaft.
1. Fit the 3rd speed driven gear (1a) using a hydraulic press, a suitable plate (1b) and the fitting tool (1c).
DescriptionCodeFunction
1c Extractor/Fitting tool1.870.658.000Reassembling layshaft
1. Fit the spacer.- Heat the 4tht speed driven gear to 120 °C.2. Fit the 4th speed driven gear (2a) using a hydraulic press, a suitable plate (2b) and the top part of the tool (2c).
DescriptionCodeFunction
2c Extractor/Fitting tool1.870.658.000Reassembling layshaft
1. Fit the 5th speed driven gear (1a) using a hydraulic press, a suitable plate (1b) and the top part of the tool (1c).
DescriptionCodeFunction
1c Extractor/Fitting tool1.870.658.000Reassembling layshaft
1. Fit the 6th speed driven gear (1a) using a hydraulic press, a suitable plate (1b) and the top part of the tool (1c).
DescriptionCodeFunction
1c Extractor/Fitting tool1.870.658.000Reassembling layshaft
1. Fit the rear bearing (1a) using a hydraulic press, a suitable plate (1b) and the fitting tool (1c).
DescriptionCodeFunction
1c Fitting tool1.870.659.000,Reassembling layshaft
- Fit the main and layshafts simultaneously in their housings.- If the main shaft, bellhousing, gearbox casing, layshaft rear bearing, layshaft assembly, 3rd, 4th,5th and 6th speed driven gears are being replaced, determine the size of the scraper shims for the main and layshaft bearing pre-loading following the instructions given below.- Thoroughly clean the bearing and gearbox casing support surfaces.1. Position the two gauges in the rear bearing seats in the gearbox casing.
DescriptionCodeFunction
1 Gauges1.870.648.000Determining main and layshaft bearing pre-loading
1. Fit the reference crossmember on the gearbox casing.
DescriptionCodeFunction
1 Reference crossmember1.870.649.000Determining main and layshaft bearing pre-loading
1. Place the two cylinders for the gauges in contact (without force) with the lower surface of the reference crossmember using a screwdriver and working via the two special openings2. Lock the two cylinders using the bolts.
- Remove the reference crossmember and the gauges from the gearbox casing.1. Fit the gauges on the plate
DescriptionCodeFunction
1 Gauges1.870.648.000Determining main and layshaft bearing pre-loading
1. Fit the tool for checking the bearing pre-loading (1a) with the bolts (1b), the spacer (1c), the disc (1d) and the centering bush (1e) specially designed for 6 speed gearboxes.
DescriptionCodeFunction
1a Support1.870.647.000Determining main and layshaft bearing pre-loading
1. Match the support for determining the bearing pre-loading kitted out in this way with the base plate complete with gauges.2. Connect the tool to a compressed air line and supply it with a pressure of 0.5 bar so that the two actuators are in contact with the gauges.3. Fit two dial gauges on the tool and zero them with a pre-loading of 3 mm (see reference X in the example for calculating the scraper shims).
DescriptionCodeFunction
3 Dial gauges1.895.881.000Determining main and layshaft bearing pre-loading
- Remove the support for determining the bearing pre-loading from the base plate complete with gauges.1. Remove the disc.
- Fit the bearing races on the main and layshafts.1. Position the support for determining the bearing pre-loading on the gearbox casing support and tighten it to torque.
Value - daNmFasteningComponentØ  
.3.1 - 4.5BoltMANUAL GEARBOX (6 speed-
2. Connect the equipment to an air line and supply it at a pressure of 4 bar.3. Rotate the main and layshafts through ten revolutions using the tool (3a) and a suitable crank (3b).
DescriptionCodeFunction
3a Bush1.870.652.000Main shaft rotation
- Measure the movements in relation to the layshaft and the main shaft using the dial gauges (see reference Y in the example for calculating the scraper shims).- Add 0.15 mm to the difference between X and Y for the layshaft to obtain the necessary distance for selecting the size of the scraper ring to be used.- Subtract 0.10 mm from the difference between X and Y for the main shaft to obtain the necessary distance for selecting the size of the scraper ring to be used.
Below is an example for calculating the size of scraper shims.
- Reference distance Y (shafts)- To simplify the situation, let us assume that the difference measured was 0.9 mm for both the layshaft and the main shaft.
- Calculation of layshaft scraper shim.- 0.15 mm must be added to the difference measured between X and Y; to understand this more easily, immagine that the pointer has to move to the test distance of 0.15 mm, i.e.: 0.9 + 0.15 = 1.05 mm (scraper shim).
- Calculation of main shaft scraper shim.- 0.10 mm must be subtracted from the difference measured between X and Y; to understand this more easily, immagine that the pointer has to move to the test distance of 0.10 mm, i.e.: 0.9 -0.10 = 0.80 mm (scraper shim).
- Remove the tool for determining the bearing pre-loading from the gearbox casing support.1. Fit the lubrication duct.2. Fit the main shaft scraper ring of the size calculated.3. Fit the main shaft rear bearing outer race (3a) using a hydraulic press, a suitable plate (3b) and the fitting tool (3c).
DescriptionCodeFunction
3c Fitting tool1.874.365.000Fitting main shaft rear bearing outer race
1. Fit the layshaft scraper ring of the size calculated.2. Fit the main shaft rear bearing outer race (2a) using a hydraulic press, a suitable plate (2b) and the fitting tool (2c).
DescriptionCodeFunction
2c Fitting tool1.874.365.000Fitting layshaft rear bearing outer race
- Fit the reverse shaft and 1st, 2nd, 3rd and 4th speed forks and control rods.1. Lift up the reverse driven gear and check that the reverse shaft pin is correctly positioned.
1. Fit the 5-6th speed and reverse control forks.2. Fit the 5-6th speed and reverse control rod (2a) and secure it tightening the bolt (2b) to the recommended torque.
Value - daNmFasteningComponentØ  
2b 2.3 - 3.3Bolt5TH SPEED CONTROL RODM8
3. Fit the 5th speed control fork (3a) and secure it tightening the bolt (3b) to the recommended torque.
Value - daNmFasteningComponentØ  
3b 2.3 - 3.3Bolt5TH SPEED CONTROL FORKM8
- Apply the recommended sealant to the entire surface matched with the gearbox casing.
DescriptionQty.ComponentTypeClassification
.Loctite 510-GEARBOX COMPONENTSSealant-
1. Fit the gearbox casing (1a) and secure it tightening the bolts (1b) to the recommended torque.
Value - daNmFasteningComponentØ  
1b 3.1 - 4.5BoltGEARBOX COMPONENTSM9
2. Tighten the reverse shaft bolt to the recommended torque.
Value - daNmFasteningComponentØ  
2 4.6 - 6.6BoltREVERSE GEAR SHAFTM10
- Fit the magnet.- Fit the differential in its housing complete with bearing outer races.- Apply the recommended sealant to the entire surface matched with the differential internal housing support.
DescriptionQty.ComponentTypeClassification
.Loctite 510-DIFFERENTIAL INTERNAL CASING SUPPORTSealant-
1. Fit the differential internal housing support (1a) and secure it tightening the bolts (1b) to the recommended torque.
Value - daNmFasteningComponentØ  
1a 4.6 - 6.6BoltDIFFERENTIAL INTERNAL CASING SUPPORTM10
Value - daNmFasteningComponentØ  
1b 2.3 - 3.3BoltDIFFERENTIAL INTERNAL CASING SUPPORTM8
1. Fit a new seal (1a) on the flange (1b) using the tools (1c) and (1d) and secure it to the gearbox side differential using the bolts (1e).
DescriptionCodeFunction
1c Fitting tool1.870.597.000Fitting seal
DescriptionCodeFunction
1d Grips1.870.007.000Fitting seal
Value - daNmFasteningComponentØ  
1e 2.3 - 3.3BoltFLANGES ON DIFFERENTIALM8
- Using a suitable drift, move the pinion side tapered bearing outer race nearer.1. Position the tool complete with dial gauge on the surface of the engine side differential and zero the dial guage with a pre-loading of 1 mm.
DescriptionCodeFunction
1 Support1.895.655.000Determining thickness of differential bearing scraper rings
1. Position the tool (1a) complete with dial gauge on the engine side differential flange (1b) and measure the difference.
DescriptionCodeFunction
1a Support1.895.655.000Determining thickness of differential bearing scraper rings
- Calculate the size of the differential bearign pre-loading scraper ring adding 0.12 mm to the difference measured.
0.12 corresponds to the recommended interference for the bedding in and pre-loading of the differential bearings.
1. Place the scraper ring or rings of the same size or the next (larger) size to that calculated for the differential bearing pre-loading in the housing.2. Fit a new seal (2a) on the flange (2b) using the tools (2c) and (2d) and secure it to the gearbox side differential using the bolts (2e).
DescriptionCodeFunction
2c Fitting tool1.870.597.000Fitting seal
DescriptionCodeFunction
2d Grips1.870.007.000Fitting seal
Value - daNmFasteningComponentØ  
2e 2.3 - 3.3BoltFLANGES ON DIFFERENTIALM8
3. Fit the clutch actuator (3a) complete with oil seal panel to the main shaft securing it by tightening the bolts (3b) to the recommended torque.
Value - daNmFasteningComponentØ  
3b 2.3 - 3.3BoltCLUTCH CONTROL HYDRAULIC ACTIVATORM6
- Fit the clutch engagement thrust bearing control fork pin.- Fit the outer non-slip bush.- Fit the left inner driveshaft.- Undo the fastenings and remove the gearbox and differential from the tool.
Two mechanics are needed for this operation.
DescriptionCodeFunction
.Support1.871.001.014Positioning gearbox and differential on overhaul stand
- Remove the support tool from the overhaul stand and put it down.- Position the gearbox and differential on the tool used for the removing-refitting from the vehicle.