MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
162
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 4-4-14 Removing sequence for the
cylinder body bolts
Fig. 4-4-15 Installing the plastic rope
clearance gauge
Fig. 4-4-16 Measuring the width of the plastic
gauge
2. Checking the clearance of crankshaft main
shaft bearing shell
(1) Remove the 10 main bearing cap bolts orderly as
per Fig. 4-4-14, and remove the lower cylinder body.
(2) Remove the crankshaft and the main shaft bearing
shell.
(3) Clean the surface of the main bearing journal of
crankshaft and the upper and the lower main shaft
bearing shells.
(4) Check the main shaft bearing shells for damage and
wear.
Attention:
Check and replace the excessively
worn or damaged main shaft bearing shell.
(5) Install the upper shaft bearing shell and the thrust
plate to their original position. And install the crankshaft
carefully.
(6) Install the lower shaft bearing shell to its original
poison of the lower cylinder body.
(7) Install the plastic gauge to the main bearing journal
of crankshaft as per Fig. 4-4-15.
(8) Install the lower cylinder body, coat the fitting
surface and the thread of its main bearing cap bolt with
engine oil, and screw down the 10 main bearing cap
bolts to specified torque in three steps.
Mobil API CI-4 lubricating oil
Tightening torque for main bearing cap bolt
Step 1
Step 2
Step 3
40 N·
m±3 N·
m
Turn for 90°
Turn for another
90°
Attention:
The crankshaft should not be rotated.
(9) Remove the lower cylinder body.
(10) Measure the width of the plastic gauge, and
confirm the oil clearance (See Fig. 4-4-16).Replace the
main shaft bearing shell in group and/or the crankshaft
if the oil clearance exceeds specified limit value.
(11) Remove the plastic gauge from the main shaft
bearing shell and the crankshaft.
(12) Remove the crankshaft and the main shaft bearing
shell.
Oil clearance
