Yanmar 3JH4BE - Page 133

5. Inspection and Servicing of Basic Engine Parts
117
(3) Camshaft and bearing hole measurement
Measure the camshaft outside diameter with a
micrometer. The oil clearance shall be calculated by
subtracting the measured camshaft outside diameter
from the inside diameter of the camshaft bearing or
bushing. The camshaft bushing at gear case side is
measured with a cylinder gage after insertion to the
cylinder.
Replace if they exceed the limit or are damaged.
(4) Bending of the camshaft
Support both ends of the camshaft with V-blocks, place
a dial gauge at the central bearing areas and measure
bending. Replace if excessive.
NOTE:
The reading on the dial gauge is divided by two to
obtain the camshaft bend.
mm
Place Item Standard Limit
Gear side
Bushing I.D. 44.990-45.055 45.130
Camshaft
O.D.
44.925-44.950 44.890
Oil
clearance
0.040-0.130 0.240
Intermediate
position
Bushing I.D. 45.000-45.025 45.100
Camshaft
O.D.
44.910-44.935 44.875
Oil
clearance
0.065-0.115 0.225
Flywheel
side
Bushing I.D. 45.000-45.025 45.100
Camshaft
O.D.
44.925-44.950 44.890
Oil
clearance
0.050-0.100 0.210
mm
Standard Limit
Camshaft bend 0.02 or less 0.05
Flywheel side
Micrometer
(Camshaft outside diameter)
(Camshaft bend)
Dial gage
V-block