2110B34 4 SPEED GEARBOX GEARS, SHAFTS AND BEARINGS - REPLACE FOLLOWING OPERATION 2110B20 - Alfa - 156 - eLearn

3239114 - 2110B34 4 speed gearbox gears, shafts and bearings - replace following operation 2110b20

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

Two operators are needed for this operation.

	Name	Country
1b	Support	1.871.001.014

1. Undo the bolts (1a), extract the retaining clip (1b) and remove the coaxial clutch operating 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 degrees 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.

	Name	Country
2	Blade	1.870.718.000

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

1. Extract the main shaft (A) (1a) and first layshaft (B) (1b) assemblies at the same time complete with 1st-2nd and 5th-6th speed selector forks.

Keep the units assembled until they are placed on the workbench.

For quick identification, each control shaft has a corresponding letter: main shaft (A), first layshaft (B) and second layshaft (C), as illustrated.

1. Extract the layshaft (C) upwards complete with 3rd-4th speed and Reverse selector forks.2. Remove the differential assembly.

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

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

	Name	Country
1a	Gearbox casing/clutch casing support	1.870.897.700

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

1. Remove the gearbox casing oil channel.2. Remove the lubrication ducts by the main and layshafts using pliers.

The lubrication ducts are destroyed during the removal operation so new components must be used when refitting.

3. Remove the main and layshaft rear bearing outer track using a USAG 468/2 type bridge and USAG 468/7 extractor or similar tools.

To facilitate the recognition of each shaft housing, the housing for the main shaft is identified by the letter (A), the housing for the first layshaft by the letter (B) and the housing for the second layshaft by the letter (C). The removal 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 manget for collecting any impurities in the transmission fluid from the clutch casing. 2. Remove the main and layshaft front bearings outer race using a USAG 468/2 type bridge and USAG 468/7 extractor or similar tools.

Proceed with dismantling the main shaft (A), following the instructions given below.1. Position the main shaft (A) (1a) in a vice fitted with protective jaws, then undo the bolt (1b) retaining the 4th speed drive gear (1c) and the 6th speed drive gear (1d).

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

	Name	Country
1	Half-plate	1.860.837.000

2. Using the press fitted with a reaction pin (2a), remove the rear bearing (2b), 6th speed drive gear (2c), 4th speed drive gear (2d) and spacer (2e).

Support the main shaft (A) underneath during this operation.

	Name	Country
2a	Reaction pin	1.870.899.100

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

Support the main shaft (A) underneath during this operation.

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Reaction pin	1.870.899.100

1. Fit the extracting half-rings (1a) in the housing in the extactor (1b); position the tools assembled in this way on the main shaft (A) front bearing and lock them using the nuts (1c).

	Name	Country
1a	Extractor half-rings	1.870.899.200

	Name	Country
1b	Extractor	1.870.845.100

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

Support the main shaft (A) underneath during this operation.

Proceed with dismantling the layshaft (B), following the instructions given below.1. Remove the 1st and 2nd speed selector fork (1a) and 5th and 6th speed selector fork from the layshaft (B).

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

	Name	Country
1	Half-plate	1.860.837.000

2. Using the press fitted with a reaction pin (2a), remove the rear bearing (2b), the 6th speed driven gear (2c) and the needle bearing (2d).

Support the layshaft (B) underneath during this operation.

	Name	Country
2a	Reaction pin	1.870.899.100

1. Remove the 6th speed synchronizer ring set.2. Remove the 5th-6th speed engagement sliding sleeve.3. Remove the pre-synchronizer mountings.

1. Remove the circlip retaining the 5th-6th speed sliding sleeve hub using suitable pliers.

When refitting, replace the circplip.

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

	Name	Country
1e	Half-plates	1.870.899.400

	Name	Country
1f	Reaction pin	1.870.899.100

2. Remove the needle bearing.

Support the layshaft (B) underneath during this operation.

1. Lift up the retaining ring (1a), then remove the thrust washers (1b) retaining the 2nd speed driven gear, releasing them from the housings (1c) on the layshaft (B). 2. Remove the 2nd speed driven gear (2a), the needle bearing (2b), the and the 2nd speed synchronizer rings (2c).3. Remove the 1st-2nd speed engagement sliding sleeve.4. Remove the pre-synchronizer mountings.

1. Remove the circlip retaining the 1st-2nd speed sliding sleeve hub using suitable pliers.

When refitting, replace the circplip.

1. Remove the 1st-2nd speed sliding sleeve hub (1a), the 1st speed synchronizer ring set (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).

	Name	Country
1e	Half-plate	1.860.837.000

	Name	Country
1f	Reaction pin	1.870.899.100

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

Support the layshaft (B) underneath during this operation.

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

	Name	Country
1a	Extractor half-rings	1.870.899.600

	Name	Country
1b	Extractor	1.870.845.100

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

Support the layshaft (B) underneath during this operation.

Proceed with dismantling the layshaft (C), following the instructions given below.1. Remove the 3rd-4th speed selector fork (1a) and Reverse selector fork (1b) from the layshaft (C).

1. Position the reaction plates on the press support surface and fit them on the layshaft (C) by the 4th speed driven gear.

	Name	Country
1	Half-plates	1.870.899.400

2. Using the press fitted with a reaction pin (2a) remove the rear bearing (2b), the 4th speed driven gear (2c) and the needle bearing (2d).

Support the main shaft (A) underneath during this operation.

	Name	Country
2a	Reaction pin	1.870.899.100

1. Remove the 4th speed synchronizer ring set.2. Remove the 3rd-4th speed engagement sliding sleeve. 3. Remove the pre-synchronizer mountings.

1. Remove the hub circlip for the 3rd and 4th speed sliding sleeve using suitable pliers.

When refitting, replace the circplip.

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

	Name	Country
1d	Half-plate	1.860.837.000

	Name	Country
1e	Reaction pin	1.870.899.100

2. Remove the needle bearing.

Support the layshaft (C) underneath during this operation.

1. Fit the extraction half-rings (1a) in the housing in the extractor (1b); position the tools assembled in this way on the spacer between the 3rd-4th speed and Reverse gears and lock them using the nuts (1c).

	Name	Country
1a	Extractor half-rings	1.870.899.700

	Name	Country
1b	Extractor	1.870.845.100

2. Position the layshaft (C), complete with extraction tools, on the press support surface, then proceed with extracting the spacer between the 3rd-4th speed and Reverse gears (2a) using the reaction pin (2b).

Support the layshaft (C) underneath during this operation.

	Name	Country
2b	Reaction pin	1.870.899.100

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 circplip.

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

	Name	Country
1d	Half-plate	1.860.837.000

	Name	Country
1e	Reaction pin	1.870.899.100

2. Remove the needle bearing.

Support the layshaft (C) underneath during this operation.

1. Remove the spacer under the Reverse driven gear.

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

	Name	Country
1a	Extractor half-rings	1.870.899.500

	Name	Country
1b	Extractor	1.870.845.100

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

Support the layshaft (C) underneath during this operation.

When working on the differential, proceed as described below.1. Remove the rear differential bearing outer race using a USAG 468/2 type bridge and USAG 468/8 extractor or similar tools. 2. Remove the differential scraper ring underneath.

1. Remove the seal on the differential internal shaft, left drive shaft side from the gearbox casing using a drift.

Removing the seal destroys it, so a new seal must be fitted.

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

1. Remove the seal on the differential internal shaft, right drive shaft side from the clutch casing using a drift.

Removing the seal destroys it, so a new seal must be fitted.

- 2110D26 differential inner case bearings - replace with differential inner case removed . When replacing the following components: differential assembly, differential front bearing, differential rear bearing, gearbox casing, determine the size of the scraper ring for the differential bearing pre-loading so that the correct alignment between the ring gear and the layshaft gears is maintained; proceed as described below. Thoroughly clean the support surfaces of the bearings and gearbox casing. - 2110D26 differential inner case bearings - replace with differential inner case removed . 1. Position the gearbox casing supported by the tool (1a) on the press support surface, fit the scraper ring (1b) removed previously in its housing and the differential rear bearing outer race (1c).

	Name	Country
1a	Gearbox casing/clutch casing support	1.870.897.700

2. Proceed with fitting the rear bearing outer race using the drift (2a) and the grip (2b).

	Name	Country
2a	Drift	1.870.898.500

	Name	Country
2b	Grip	1.870.898.400

Remove the gearbox casing from the support tool.

	Name	Country
-	Gearbox casing/clutch casing support	1.870.897.700

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

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

	Name	Country
1a	Gearbox casing/clutch casing support	1.870.897.700

2. Position the clutch casing (2a) on the support tool as illustrated, 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, then fit the differential front bearing outer race (1b) in its housing.

	Name	Country
1a	Gearbox casing/clutch casing support	1.870.897.700

2. Proceed with fitting front bearing outer race using the drift (2a) and the grip (2b).

	Name	Country
2a	Drift	1.870.898.500

	Name	Country
2b	Grip	1.870.898.400

Proceed with determining the size of the differential bearing pre-loading scraper ring; 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.

	Fastening	Component	Ø	Value(daNm)
2b	Bolt	GEARBOX GEAR CASING	M8	(to clutch casing) a scatola frizione.

	Fastening	Component	Ø	Value(daNm)
2c	Bolt	GEARBOX GEAR CASING	M10	(clutch casing) 5

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

This operation prevents the inner rotation of the planet and satellite gears as they rotate with the differential housing.

	Name	Country
1a	Splined shaft	1.870.898.200

2. Fit a gauge for measuring the rolling torque on the tool; rotate the differential through several revolutions and measure the torque.

	Measurement		Value
2	Differential rolling torque (daNm)		1.5 - 2.0

If the differential rolling torque is within the recommended range given in the table, the size of the differential baring pre-loading washer is correct. If the differential rolling torque figure is lower than the one given in the table, remove the differential bearing pre-loading washer, following the instructions given previously, fit a larger washer and then repeat the test for determining the differential rolling torque until the value is correct. If the differential rolling torque figure is higher than the one given in the table, remove the differential bearing pre-loading washer, following the instructions given previously, fit a smaller washer and then repeat the test for determining the differential rolling torque until the value is correct.

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

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

1. Fit the Reverse sliding sleeve hub (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 presynchronizer mountings on the hub and on the Reverse synchronizer rings.

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

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

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

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

1. Fit the 3rd speed driven gear.2. Fit the needle bearing for the 3rd speed driven gear.3. Fit the 3rd speed synchronier ring set.

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

1. Fit the 3rd-4th speed sliding sleeve hub (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 presynchronizer mountings on the hub andon the 3rd speed synchronizer rings.

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

1. Fit a new 3rd-4th speed sliding sleeve hub circlip.2. Place the pre-synchronizer mountings on the sliding sleeve hub back in their housings.3. Fit the 3rd and 4th speed sliding sleeve.4. Fit the 4th speed synchronizer ring set.

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

5. Fit the 4th speed synchronizer ring set.6. Fit the needle bearing for the 4th speed driven gear.

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

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Fitting tool	1.860.824.000

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

	Name	Country
1a	Half-plate	1.860.837.000

	Name	Country
1b	Fitting tool	1.860.824.000

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

	Name	Country
2b	Fitting tool	1.870.710.000

1. Position the Reverse selector fork (1a) on the sliding sleeve (1b).2. Position the 3rd-4th speed selector fork (2a) on the Reverse selector fork and then on the 3rd-4th speed seliding sleeve (2b).

Check that the synchronisers turn freely without tightness.

After having thoroughly washed all the components dismantled and checked that they are intact, reassemble the layshaft (B) following the instructions. 1. Fit the 1st speed lower roller bearing (inner chamber in line with the rollers).2. Fit the 1st speed driven gear.3. Fit the 1st speed upper roller bearing (outer chamber in line with the rollers).4. Fit the 1st speed synchronizer ring set.

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

1. Fit the 1st-2nd speed sliding sleeve hub (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 presynchronizer mountings on the hub and on the 1st speed synchronizer rings.

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

1. Fit a new 1st-2nd speed sliding sleeve hub circlip.2. Place the pre-synchronizer mountings on the sliding sleeve hub back in their housings.3. Fit the 1st-2nd sliding sleeve.4. Fit the 2nd speed synchronizer ring set.

Check that the synchronizer teeth are fully engaged in the grooves on the sliding sleeve hub.

5. Fit the 2nd speed driven gear.6. Fit the needle bearing for the 2nd speed driven gear.

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

1. Fit the 5th speed driven gear needle bearing.2. Fit the 5th speed driven gear.3. Fit the 5th speed synchronizer ring set.

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

1. Fit the 5th-6th speed sliding sleeve hub (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 presynchronizer mountings on the hub and on the 5th speed synchronizer rings.

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

2. Fit a new 5th-6th speed sliding sleeve hub circlip.

1. Fit the presynchronizer mountings in the housings in the 5th-6th speed sliding sleeve hub.2. Fit the 5th-6th speed sliding sleeve.3. Fit the 6th speed synchronizer ring set.4. Fit the 6th speed driven gear.

Check that the synchronizer teeth are fully engaged in the grooves on the gear.

5. Fit the 6th speed driven gear needle bearing.

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

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Fitting tool	1.860.824.000

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

	Name	Country
1a	Half-plate	1.860.837.000

	Name	Country
1b	Fitting tool	1.860.824.000

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

	Name	Country
2b	Fitting tool	1.870.710.000

1. Position the 1st-2nd speed selector fork (1a) on the sliding sleeve (1b).2. Position the 5th-6th speed selector fork (2a) on the 1st-2nd speed selector fork and then on the 5th-6th speed sliding sleeve (2b).

Check that the synchronisers turn freely without tightness.

After having thoroughly washed all the components dismantled and checked that they are intact, reassemble the mainshaft (A) following the instructions.1. Fit a new front bearing (1a) on the main shaft (A) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Fitting tool	1.870.899.300

1. Fit the 3rd-5th speed drive gear (1a) on the main shaft (A) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

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

	Name	Country
2b	Half-plate	1.860.837.000

	Name	Country
2c	Tool for Extracting/Fitting	1.870.658.000

1. Fit the 6th speed drive gear (1a) on the main shaft (A) using a hydraulic press, the half-plates (1b) and the fitting tool (1c).

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Tool for Extracting/Fitting	1.870.658.000

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

	Name	Country
1b	Half-plate	1.860.837.000

	Name	Country
1c	Fitting tool	1.860.824.000

1. Position the main shaft (A) in a vice fitted with protective jaws, then tighten the 6th speed drive gear retaining bolt to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
1	Bolt	SPLINED CLUTCH MAINSHAFT	M20 x 1.5	4.5

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

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

	Name	Country
1a	Gearbox casing/clutch casing support	1.870.897.700

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

To allow quick identification, each shaft has a corresponding letter: main shaft (A), first layshaft (B) and second layshaft (C), as illustrated.

	Name	Country
3a	Fitting tool	1.870.898.900

	Name	Country
3b	Fitting tool	1.870.898.700

	Name	Country
3c	Fitting tool	1.870.898.800

	Name	Country
3d	Grip	1.870.898.400

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

	Name	Country
-	Support	1.871.001.014

Fit the magnet for collecting impurities in the transmission fluid in the clutch casing.1. Position the layshaft (C), complete with 3rd-4th speed and Reverse selector forks in the housing (C) in the clutch casing.

1. Position the main shaft (A) (1a) and layshaft (B) (1b) assemblies complete with 1st-2nd and 5th-6th speed selector forks in the housings (A) and (B) in the clutch casing.

When replacing the following components: main shaft, gearbox casing, main shaft (A) front bearing, main shaft (A) rear bearing, layshaft (B) assembly, layshaft (C) assembly, layshaft (B) rear baring, layshaft (C) rear bearing, determine the size of the washers for the main shaft (A), layshaft (B) and layshaft (C) bearing pre-loading following the instructions below. Clean the gearbox casing, the bearing support surfaces and the planes joined with the clutch casing thoroughly.1. Position the gearbox casing (1a) on the support tool (1b) as illustrated in the diagram, by the pins (1c) marked with the letter (A) tightened in the openings (A); the secure the gearbox casing using the nuts (1d).

	Name	Country
1b	Gearbox casing/clutch casing support	1.870.897.700

1. Position 3 depth gauges (1a) by the rear bearing outer race seats (1b) on the gearbox casing.

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

	Name	Country
1a	Depth gauges	1.870.898.000

1. Fit the reference crossmember (1a) on the gearbox casing and secure it using the nuts (1b).

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

	Name	Country
1a	Reference crossmember	1.870.897.800

Determining the height of the gearbox casing (shaft housing)1. Loosen the bolts (1a) by each depth gauge; in this way the springs inside the gauges place the cylinders (1b) in contact with the reference crossmember lower surface; lock the bolts loosened previously in this position.

The height of the depth 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 depth gauages from the gearbox casing.1. Fit the three gauges (1a) on the tool plate (1b).

	Name	Country
1a	Depth gauges	1.870.898.000

	Name	Country
1b	Support for depth gauges	1.870.897.900

1. Match the support for determining the bearing pre-loading complete with dial gauges (1a) on the support plate complete with depth gauges (1b).

Position the support for determining the bearing pre-loading as illustrated in the diagram in order to align the references A-A, B-B and C-C with the shafts.

	Name	Country
1a	Support complete with dial gauges for determining	1.870.898.100

	Name	Country
1b	Support for depth gauges	1.870.897.900

2. Fasten the support for determining the bearing pre-loading to the plate using the special bolts.3. Zero the pointers for the dial gauges with a pre-loading of 3 mm for each depth 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 the special bolts.3. Rotate the main and layshafts through ten revolutions using the tool (3a) and a suitable crank (3b).

	Name	Country
3a	Bush for main shaft counter-torque	1.870.899.000

Using the three dial gauges, measure the differences for the main shaft (A), the layshaft (B) and the layshaft (C). To determine the size of the main shaft (A) scraper ring to be used from those that are available as spares, subtract 0.01 to 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 those that are available as spares, add 0.05 to 0.10 mm, corresponding to the bearing pre-loading to the difference measured. Remove the tool for determining the bearing pre-loading from the gearbox casing.1. Fit the lubrication duct.2. Fit the main shaft (A) adjustment ring in 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).

	Name	Country
3b	Gearbox casing/clutch casing support	1.870.897.700

	Name	Country
3c	Fitting tool	1.870.898.600

	Name	Country
3d	Grip	1.870.898.400

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

	Type	Component	Name	Qty.
-	Sealant	GEARBOX GEAR CASING	Loctite 510	-

Remove the gearbox casing from the support tool.

	Name	Country
-	Gearbox casing/clutch casing support	1.870.897.700

Fit the gearbox casing on the clutch casing tightening the bolts to the recommended torque.

	Fastening	Component	Ø	Value(daNm)
-	Bolt	GEARBOX GEAR CASING	M8	(to clutch casing) a scatola frizione.

	Fastening	Component	Ø	Value(daNm)
-	Bolt	GEARBOX GEAR CASING	M10	(clutch casing) 5

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

	Name	Country
1b	Fitting tool	1.870.899.800

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

	Name	Country
1b	Fitting tool	1.870.899.800

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

	Fastening	Component	Ø	Value(daNm)
-	Bolt	GEARBOX GEAR CASING	M10	(clutch casing) 5

Fit the coaxial clutch operating cylinder and secure using the fixing bolts.

	Fastening	Component	Ø	Value(daNm)
-	Bolt	CLUTCH CONTROL HYDRAULIC ACTIVATOR	M6	(clutch casing) 1

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

Two operators are needed for this operation.

	Name	Country
-	Support	1.871.001.014

Remove the tool supporting the overhaul stand and put it back.