MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
326
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 5-16-8 Removing the carbon deposits on
the upper part of cylinder wall
Fig. 5-16-9 Marking the connecting rod
bearing shell
Removing the connecting rod cover
⑥
(1) Respectively remove the 8 connecting rod bolts for
tightening the connecting rod cover under the
crankshaft, and take down 4 connecting rod covers and
4 lower connecting rod bearing shells. See Fig. 5-16-7.
(2) If the removed lower connecting rod bearing shells
can be reused, hang a label on each bearing shell (see
Fig. 5-16-7) to indicate the sequential number of each
cylinder and the installation position.
(3) Check the thread of the connecting rod bolts for
damage or stretching, and replace them if damaged.
Removing the piston and connecting rod assembly
⑦
(1) Before removing the piston and connecting rod, use
a scraper to clear the carbon deposits on the upper part
of cylinder wall. See Fig. 5-16-8.
(2) Move the piston to the top of the cylinder and push
the lower part of the connecting rod with a hammer
handle or something similar; take out the piston and the
connecting rod.
Caution:
Take care during removal. Do not impact
or scratch the connecting rod journal and the internal
surface of the cylinder.
(3) If the removed upper connecting rod bearing shells
can be reused, hang a label on each bearing shell. See
Fig. 5-16-9.
Prompt:
The removed piston and connecting rod
assemblies should be placed in pair and by group to
ensure correct installation.
Fig. 5-16-10 Removing the piston ring
Removing the piston ring
⑧
(1) Use a piston ring expander to remove the two
compression rings and one oil ring component
respectively.
See Fig. 5-16-10.
(2) Place the removed piston rings properly according
to the cylinder number.
Caution:
Do not try to use other tools to remove
the piston rings. Excessive tension of the piston rings
will impair their elasticity.
