Ducati Diavel Workshop Manual page 810

Crankcase assembly: crankcase halves
The roller bearing (15) with retaining circlip (16) installed in correspondence with the end of the timing belt driveshaft.
Insert the circlip (5) in the crankcase half installing it in its seat on the bearing (4).
Refitting the alternator-side crankcase half
The following parts must be present on the internal side of the crankcase half:
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).
Note
The bearing retaining plate must be positioned so that the countersunk side is facing upwards.
Tighten the screws (11) to a torque of 10 Nm (Min. 9 Nm - Max. 11 Nm) (Sect. 3 - 3, Engine torque settings).
Lubricate the ring (6) with denatured alcohol, drive it fully home against the crankcase half, and orient it as shown.
The primary shaft bearing (7) with internal spacer (6), oriented so that the closed side of the plastic roller cage (M) faces