MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
186
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 4-5-23 Installing the piston pin and
clamping spring
Fig. 4-5-24 Piston ring installation procedure
Fig. 4-5-25 Installing the piston ring
Install the piston on the connecting rod; the forward
mark on the piston top should be on the same side with
the connecting rod forward mark. See Fig. 4-5-23.
Attention:
Do not change the combination of
piston and piston pin when the piston connecting rod
combination is not replaced.
Reinstalling the piston pin
⑨
(1) Coat the piston with an appropriate amount of
lubricating oil, and install it into the piston pin hole and
connecting rod small end hole.
Mobil API CI-4 lubricating oil
(2) Install the piston pin into the piston pin hole. After the
installation, the piston pin should move smoothly
without any seizure.
Clearance between the piston pin and the pin hole
Standard
0.005~0.012mm
Clearance between the connecting rod small end hole
and the piston pin
0.010~0.024mm
Reinstalling the clamping spring
⑧
Install the clamping springs to both ends of the piston
pin. The clamping spring should be completely installed
into the clamping spring groove and be able to move
around. Do not leave any part of the clamping spring at
the outside or on the upper part of the groove. It should
be at the bottom of the groove.
Caution:
The piston pin clamping spring must be
firmly fixed.
Reinstalling the piston ring
⑦
Install the piston ring in the piston ring groove in the
correct direction. The marks (TOPs) on the first &
second compression rings should be upwards (see Fig.
4-5-24 and Fig. 5-5-25). The piston ring should move
smoothly in the piston ring groove without any seizure.
The clearance should meet the requirements.
Attention:
——The
two
compression
rings
are
not
interchangeable.
——The piston ring should not tilt.
——No defect or foreign material in the piston ring
groove is acceptable.
Forward mark
Forward mark
The side marked (TOP)
upwards
First compression ring
Second
compression ring
Taper face
Oil ring
TOP mark
(
compression
ring
)
