MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
354
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
bearing shell
Fig. 5-19-23 Installing the connecting rod
assembly and piston
Fig. 5-19-24 Installing the piston ring
Fig. 5-19-25 Inspection for open end of piston
ring
(4) Apply an appropriate amount of lubricating oil to the
piston ring before the installation: use the piston ring
expander to install the oil ring component, the second
compression ring and the first compression ring in
proper order. See Fig. 5-19-23. The piston ring should
be installed to the piston ring groove in a correct
direction with the top marks (TOP) of the first and
second compression rings upward. See Fig. 5-19-24.
The piston ring moves smoothly in ring slot without any
stagnation, and the clearance meets the requirement
after installation.
Mobil API CI-4 lubricating oil
Attention:
——Two compression rings are not interchangeable.
——Piston ring should not tilt.
——There should not be any defect or impurity in the
piston ring groove.
The three piston rings should be installed into their
grooves with their open ends staggered as shown in
Fig. 5-19-25.
(5) Use the piston ring compressor to install the piston
connecting rod to the cylinder, as shown in Fig. 5-19-26.
Piston ring compressor: 5-8840-9018-0.
Piston cylinder clearance
0.07~0.09mm
Attention:
The front marks on the piston and the
connecting rod should face the front end of the diesel
engine.
(6) Reinstall the connecting rod cover to its originally
matched connecting rod. Install the connecting rod bolt
and tighten it as per specified torque by two steps.
Tightening torque for the connecting rod bolt
Step 1
Step 2
25N·
m±3N·
m
Turn for 90°±5
Clearance between connecting rod big end and
crankshaft crank
0.22~0.37mm
Attention:
The front end mark on the connecting
Open end of first
compression
ring
Spiral supporting
spring port
Open end of
oil ring
Front end mark
Open end of
second
compression
ring
TOP mark
(compression
ring)
