Bold reference numbers in this section identify parts not shown in the figures alongside the text, but which can be found in the exploded view diagram.

Re-use the alternator cover or a service cover with puller 88713.1749 fitted. Secure cover to crankcase half with some of the original screws and begin separation by turning the central pin of the tool.

Remove gearbox shafts and gearbox selector drum from the crankcase halves Sect. 9 - 7.2, Removal of the gearbox assembly.

Remove the screws (34), remove the pipes (33) and collect the O-rings (32).

Check that the bearings (1) and (18), and the bushings (2) and (17) are in optimum conditions. Note that the main bearings must always be changed in pairs (refer to the procedure below in “Main bearings”).

After having renewed the gearbox shaft bearings (28) and (9), secure them in the crankcase half with the spacers (21) and the retaining plate (10).

Take care not to lose the shim (6) interposed between the bearing (7) on the end of the gearbox primary shaft and the chain side crankcase half.

Check that the oilways are free of restrictions or clogging. Check the condition of locating bushes (22). If apparently distorted or loose in their seats, change them using proper tools. When the locating bushes (22) are hard to remove from casing, use a left-hand tap to force bushes out.

The main bearings have are of the angular contact type with offset inner races so that the balls transmit loads from one groove to the other along straight lines at an angle to the axis of the bearing. The angle-contact ball bearings are designed for bearing combined loading (radial-axial loads).

Bearings of this type can bear thrust loads in one direction only. In fact, under the action of a radial load inside the bearing, an axial force is created that must be counterbalanced by an axial force acting in the opposite direction; that is why these bearings are generally fitted back to back in pairs.

The main bearings supplied can be bearings with bushing (A) or flanged bearings (B) with the bushing integrated in the external ring of the bearing.

After having removed the bushing, check that the interference fit between the crankcase and the bushing, with bearing fitted, is no less than 0.03 mm, otherwise, replace the crankcase halves.

On badly worn engines, bearing outer rings may have developed clearance in the crankcase halves - normally, bearing outer rings are interference-fit in the casing.

Check that the interference fit between the crankcase and the bearings (1) and (18) installed, is not less than 0.03 mm, otherwise, replace the crankcase halves.

After installing new main bearings, shim the crankshaft as described in the paragraph “Shimming the shafts” and “Reassembly of the crankcase halves “ of this section.

The crankcase halves must be in good condition and perfectly clean. The mating surfaces must be perfectly flat and free from burrs.

the double race ball bearing (9) supporting the selector fork shaft. Apply threadlocker to the screws (11). Fit the retaining plate (10) to the gearbox secondary shaft bearing (9) screwing the screws fully into the chain-side crankcase half (11).

Tighten the screws (11) to a torque of 10 Nm (Min. 9 Nm - Max. 11 Nm) (Sect. 3 - 3, Engine torque settings).

The primary shaft bearing (7) with internal spacer (6), oriented so that the closed side of the plastic roller cage (M) faces the crank­case half. apply grease to the bearing rollers. Fit the inner race (A) removed previously from the bearing. Apply grease to the inner race.

Bearings do not have a specific mounting position (except main bearings); however it is good practice to install the bearings so that side bearing the writing is facing upwards.

Fit the mesh filter as described in Sect. 4 - 3, Changing the engine oil and filter cartridge.

Above the mesh filter seat there is a plug (19) which closes off the lubrication oilway. If it is to be renewed, apply the prescribed threadlocker to its threads.

Tighten the plug to a torque of 24 Nm (Min. 21 Nm - Max. 27 Nm) (Sect. 3 - 3, Engine torque settings).

Before assembling the crankcase halves, calculate the shims required to obtain the correct end float of the crankshaft and gear­box shafts.

After having installed the new main bearings (with bushing (A) or flanged bearings (B)) proceed as follows to determine the total “SA” height of the shimming:

Add 0.30 mm preload for crankshaft axial bearings to bed in correctly into their seats (inner rings seated inside outer ring).

Thus, we obtain:
SA=LA1+LA2+0.30-LA.

SA=SA1+SA2
where “SA1” and “SA2” represent the shims for the clutch-side crankcase half 1 and the alternator-side crankcase half 2.

In addition to the above procedure, the following is a practical shimming method, providing a guide on how to calculate the crank­shaft shim thicknesses accurately.

Install a shim of minimum thickness (1.90 mm) on each side of the crankshaft to prevent contact between the crankshaft web and the crankcase.

Fit four M8 screws in the seats indicated in figure and tighten them to a torque of 19 Nm (Min. 17 Nm - Max. 21 Nm) (Sect. 3 - 3, Engine torque settings).

Note on the dial gauge the total clearance and add a preload of (0.30 mm) plus the thickness of the shims used (1.90x2=3.8 mm).

If removed, apply threadlocker on the screw (36), insert it with the washer (37) on the crankcase half and tighten it to the torque of 8 Nm (Min. 7 Nm - Max. 9 Nm) (Sect. 3 - 3, Engine torque settings).

If removed, apply threadlocker on the dowel thread (35), tighten it to a torque of 20 Nm (Min. 18 Nm - Max. 22 Nm) (Sect. 3 - 3, Engine torque settings).

If removed, apply threadlocker on the plug (19), and tighten it to a torque of 24 Nm (Min. 21 Nm - Max. 27 Nm) (Sect. 3 - 3, Engine torque settings).

Install the O-ring (32) on its seat (A) in the crankcase half. Fit the pipe (33) in the crankcase half, inserting the end (B) fully in the O-ring. Align the hole (L) of the pipe with the threaded hole (M) in the crankcase half. Apply threadlocker to the screw (34) and start it in the threaded hole (M). Tighten the screw to a torque of 8 Nm (Min. 7 Nm - Max. 9 Nm) (Sect. 3 - 3, Engine torque set­tings).

To avoid damaging the oil seal (14) on the timing belt driveshaft, protect the threaded end of the shaft with the special protective cap 88700.5749. Dampen oil seal (14) with alcohol and fit it on the timing layshaft. Push seal until it contacts the roller bearing (4).

When refitting used components, before installing the gearbox assembly in the crankcase half, make sure that the inner races (C) of the gearbox shaft bearings are fitted into the correct bearings and have not been left on the shafts.

A table and a list of the gearbox components appear in Sect. 9 - 7.2, Reassembly of the gearbox shafts.

Insert the forks of 1st- 4th and 2nd- 3rd speed (D) in the corresponding sliding slots of the secondary shaft driven gears and insert the pin (G) in the forks: the two forks must be fitted with the number that indicates the gear facing upwards.

Insert the fork of 5th- 6th speed (E) in the primary shaft driven gear and the pin (G) in the fork (E): the fork must be fitted with the number indicating the gear facing the crankcase half.

Position the pin (G) of the forks (D) in the crankcase half. Holding the gear lever claw, position the gear drum (F) in the crankcase half.

Install the crankcase with calculated shims in the crankcase half bearing: the shims (R) of the shaft must be placed with the cham­fering facing the shaft. Position the connecting rods (H) matching the corresponding seats of the cylinder.

Make sure that the connecting rods (H) are correctly positioned in the cylinders. Incorrect positioning of the connecting rods at this stage will inevitably lead to the need to re-open the crankcase half.

Apply a uniform and continuous bead of DUCATI liquid gasket to the mating surfaces of the crankcase halves, going around all the holes as shown in the figure.

Apply the recommended grease to the screws and insert them in the crankcase halves (note that the screws are different lengths). Start with the larger diameter screws (M8), and follow the order indicated.

Tighten all screws to the torque indicated below (Sect. 3 - 3, Engine torque settings).

Check that the crankshaft can be turned with a certain amount of interference with the main bearings (the crankshaft should have a pre-load of 0.20 to 0.30 mm); check also that all the parts you have fitted are free to rotate or move correctly.

Install the cover to reach the mesh filter (Sect. 4- 3, Changing the engine oil and filter cartridge).

Install the cartridge filter (Sect. 4 - 3, Changing the engine oil and filter cartridge).

Install the bushing of the tool with code 88713.2060 on the secondary shaft. Lubricate the new ring (8) and seat it.