Refitting the primary drive gear
Fully degrease the crankshaft splined end and the corresponding spline on the primary drive gear. Make sure that key (9) and inner spacer (10) are duly positioned onto crankshaft.
Fit the driving gear (8) onto the crankshaft with the oil pump drive sprocket facing the crankcase.
Temporarily secure the gear with the washer (6) and nut (7).
Important
If fitting a new primary driving gear (8), check the backlash.
To check the backlash, temporarily fit the clutch housing (1) complete with inner spacer, driven gear (3) and inner ring on gearbox primary shaft.
Fix a dial gauge to the engine crankcase, positioning the stylus against a gear tooth.
Turn the driven gear (3) to mesh the teeth and check that clearance ranges between 0.05 and 0.07 mm.
Repeat the check at 16 different points of the driven gear.
If the measured values are outside the permissible tolerance limits, try changing the position of driven gear (3) on the primary shaft, leaving the driving gear (8) on the crankshaft.
If the clearance is still outside the tolerance limits, replace the primary drive gear: gear (3) and gear (8).
After backlash has been checked, lock gear (8) in place with tool part no. 88713.0137, smear nut (7) with recommended grease, and tighten it to a torque of 190 Nm (Min. 171 Nm - Max. 209 Nm).
Stake washer (6) on nut (7).
Refit the oil pump and check the backlash between the oil pump gear and primary drive gear on the crankshaft.
Thoroughly degrease mating surfaces of clutch housing (1), inner ring (4) and inner spacer (5).
Insert inner spacer (5) onto primary shaft, with the flat side facing outwards.
Fit inner ring (4), clutch housing (1) with driven gear (3) and needle roller bearing (2).
Refit the clutch unit (Refitting the clutch).
Refit the clutch cover (Refitting the clutch cover).
Fill the engine with oil (Changing engine oil and filter cartridge).