Yanmar 3YM30 Sevice Manual page 105

(5) Mounting the main bearing cap
Coat the lower main bearing metal with engine oil, and
mount it to the main bearing cap.
NOTE:
1) The lower main bearing metal does not have an
oil hole.
2) The base bearing thrust metal is fitted with the oil
groove facing outwards.
1) Coat the flange and the thread of the main bearing
bolts with engine oil, put them on the crankshaft
journal, and tighten the main bearing bolts to the
specified torque.
Tightening torque
Main bearing bolt
NOTE:
1) The main bearing cap should be mounted with
the arrow on the cap pointing towards the
flywheel.
2) Make sure to have the correct cylinder alignment
number.
2) Measure the crankshaft side clearance.
Crankshaft side
clearance
0.133-0.233
3) Make sure that the crankshaft rotates smoothly
and easily.
(6) Mounting the flywheel housing
1) Replace the used oil seal with new one. Press fit
the oil seal in the flywheel housing, and coat the lip
of the oil seal with engine oil.
2) Apply the liquid gasket on the mounting surface of
the flywheel housing and mount the flywheel
housing to the cylinder block, while matching up
with the knock pins.
NOTE:
Be careful that the liquid gasket does not protrude
onto the oil pan mounting surface.
N•m (kgf•m)
75.5-81.5 (77-8.3)
Standard Limit
0.28
4. Disassembly and reassembly
Oil hole
Lower
Main bearing cap
mm
(Journal bearing cap)
Flywheel housing
Liquid gasket
90
Upper main bearing metal
Thrust metal
Groove
Mark
Positioning number
of reassembling
Knock pin
(two)
Oil seal
Cylinder block