MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
184
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 4-5-17 Installing the piston pin
3.3 Checking the clearance between the piston pin
and the pin hole
Insert the piston pin into the piston pin hole and rotate it.
See Fig. 4-5-17.
If the piston pin moves smoothly, the clearance is
normal.
If the clearance is large or the surface is uneven,
measure the clearance.
Replace the piston or piston pin if the clearance
exceeds the limitation.
Clearance between the piston pin and the pin hole
Standard
0.005~0.012mm
Fig. 4-5-18 Replacing the connecting rod
bushing
Fig. 4-5-19 Checking the axis error of
connecting rod big & small end holes
4. Bushing
Removal: Use a suitable wood punch or a copper bar to
knock the piston pin out from the piston pin hole.
Alternatively, use a bench press for disassembly.
Installation: Use a suitable wood punch or a copper bar
to gently knock the piston pin into the piston pin hole.
Alternatively, use a bench press for assembly.
Attention:
——The connecting rod bushing should be aligned with
the oil hole on the connecting rod small end.
——After installing the new connecting rod bushing,
use a pin hole grinder to grind the bushing hole.
5. Connecting rod
5.1 Checking the axis error of connecting rod big &
small end holes
Use a connecting rod calibrator to check the axis error
of connecting rod big & small end holes. See Fig.
4-5-19.
Replace the connecting rod if the bending or torsion
exceeds the limitation.
Bending and torsion of connecting rod
Connecting rod
Standard
Bending
0.05mm or less
Torsion
0.06mm or less
5.2 Checking the axial clearance of connecting rod
Use a feeler gauge to measure the thrust clearance at
