Crankcase - crankshaft
Splitting the crankcase halves
- Before opening the crankcase, it is advisable to
check the axial clearance of the crankshaft. To do
this, use a plate and a support with a specific tool
- Higher clearances are signs of wear on the sup-
porting surfaces of the crankshaft on the crank-
- Remove the ten crankshaft coupling screws.
- Separate the crankcase while keeping the crank-
shaft in one of the two crankcase half.
- Remove the crankshaft.
- Remove the crankshaft halves coupling gasket.
- Remove the two screws and the internal cover
shown in the figure.
- Remove the flywheel side oil seal.
- Remove the oil filter fitting shown in the figure.
- Check the connecting rod axial clearance.
- Check the connecting rod radial clearance.
- Check that the surfaces that limit the axial clear-
ance are not scored and with the aid of a gauge
measure the crankshaft width as shown in the fig-
- If the crankshaft-crankcase axial clearance ex-
ceeds what specified and the crankshaft does not
show any defect, the problem must be due to ei-
ther excessive wear or wrong machining on the
- Check the diameters of both crankshaft bearings
according to the axes and surfaces shown in the
figure. Half-shafts are classified in two categories,
Cat 1 and Cat 2, as shown in the chart below. The
half-shaft category markings are stamped on the
outer side of the counterweight crankwebs.
ENG - 126