Komatsu 4D98 Series Shop Manual page 62

4. Engine Body
(5)
Parts inspection and measurement
(5-l) Camshaft
Mainly check the contact between the tappet and cam contact surface, bearing seizure and
wear, and gear damage.
@ Shaft bend measurement
Support the camshaft with V blocks.
Rotate the camshaft and measure the
runout at the center of the camshaft
and at each journal with a dial gage.
Half of the runout is the bend.
(mm)
@ Intake/exhaust cam height measurement
@ Camshaft outside diameter and bear-
ing hole diameter measurement
Measure the camshaft outside diam-
eter with a micrometer. The oil clear-
ance shall be calculated by subtracting
the measured camshaft outside diam-
eter from the the camshaft bushing in-
side diameter after insertion to the cyl-
inder measured with a cylinder gage.
I
Dial gage
Camshaft bend
Cam height
1 Camshaft outside diameter \\
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4-14