Komatsu 170-3 Series, Руководство по ремонту, Страница: 135 / 454

170-3 SERIES
12-9
TESTING AND ADJUSTING
ADJUSTING VALVE
CLEARANCE
1. Remove the cover of the flywheel housing, then
install barring device G1 .
2. Remove the cylinder head cover.
3. Using barring device G1 , rotate the crankshaft in
the normal direction to set No. 1 cylinder at com-
pression top dead center, and align pointer
b
with the [1.6TOP] line a on the crankshaft pulley.
★
At compression top dead center, the valve
rocker arm can be moved by hand by the
amount of the valve clearance. If the rocker
arm does not move, the crankshaft is not at
compression dead center, so rotate it one
more turn.
4. To adjust the valve clearance, insert feeler gauge
G2 into clearance c between rocker arm (1) and
crosshead (2), and adjust the valve clearance
with adjustment screw (3).
★
Insert the feeler gauge and turn the adjust-
ment screw until the clearance is a sliding fit.
★
Valve clearance
Intake valve: 0.32 mm
Exhaust valve: 0.62 mm
5. Tighten locknut (4) to hold adjustment screw (3)
in position.
Locknut :
57.8 – 77.4 Nm {5.9 – 7.9 kgm}
★
After tightening the locknut, check the clear-
ance again.
6. Turn the crankshaft 120° each time in the normal
direction and repeat the procedure in Steps 3 to
5 to adjust the valves of each cylinder according
to the firing order.
★
Firing order : 1 – 5 – 3 – 6 – 2 – 4
7. After completing the measurement, set to the
original condition.
Cylinder head cover mounting bolt:
9.8 ± 1.0 Nm {1 ± 0.1 kgm}
➃
ADJUSTING VALVE CLEARANCE
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