Piston and Piston Pin
PISTON AND PISTON PIN1) Check the piston and piston pin for wear or crack.
2) Check the snap ring for distortion or wear.
3) Check the piston ring groove for damage.
4) Check the circlip groove (A) for burr.
NOTE:
If the burr is found, remove the burr from groove.
5) Check that the piston pin can be inserted into the piston with a thumb at 20°C (68°F).
6) Check the clearance between piston and piston pin. Check the clearance between piston and piston pin by measuring the inner diameter of piston pin hole and the outer diameter of piston pin respectively.
(1) Using a caliper gauge, measure the inner diameter of piston pin hole.
NOTE:
- Measurement should be performed at a temperature of 20°C (68°F).
- Measure the inner diameter of the piston pin hole at the four locations as shown in the figure, and read the value of most worn location.
- Record the measured value.
(2) Measure the outer diameter of piston pin with a micrometer.
NOTE:
- Measurement should be performed at a temperature of 20°C (68°F).
- Measure the outer diameter of the piston pin at the four locations as shown in the figure, and read the value of most worn location.
- Record the measured value.
(3) Calculate the clearance between piston and piston pin. If it is not within the standard, replace the piston and piston pin as a set.
Clearance between piston and piston pin:
Standard
0.004 - 0.008 mm (0.0002 - 0.0003 in)