- Inspect the piston.
- Using a gasket scraper, remove the carbon from the top of the piston.
- Using a groove cleaning tool or broken ring, clean the piston ring grooves.
Note: Do not use a wire brush.
- Using a brush and solvent, thoroughly clean the piston.
- Using a micrometer, measure the piston diameter at right angles to the piston pin hole, and at a point 12.6 mm (0.4961 in) from the piston head.
Specification
Standard piston diameter: 80.461-80.471 mm (3.1677-3.1681 in)
- If the diameter is not as specified, replace the piston.
- Inspect piston oil clearance.
- Subtract the piston diameter measurement from the cylinder bore diameter measurement.
Specification
• | Standard oil clearance: 0.029-0.052 mm (0.0011-0.0020 in) |
• | Maximum oil clearance: 0.09 mm (0.0035 in) |
- If the oil clearance is greater than the maximum, replace all the pistons. If necessary, replace the cylinder block.
- Using a feeler gauge, measure the clearance between a new piston ring and the wall of the ring groove.
- If the groove clearance is not as specified, replace the piston.
- Using a piston, push the piston ring a little beyond the bottom of the ring travel, 50 mm (1.97 in) from the top of
the cylinder block.
- Using a feeler gauge, measure the end gap.
- If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the maximum, even with a new piston ring, replace the cylinder block.
- Using a caliper gauge, measure the piston pin bore diameter.
Specification
Standard piston pin bore diameter: 20.006-20.015 mm (0.7876-0.7880 in)
- If the diameter is not as specified, replace the piston.
- Using a micrometer, measure the piston pin diameter in three places (a,b,c).
Specification
Standard piston pin diameter: 20.004-20.013 mm (0.7876-0.7879 in)
- If the diameter is not as specified, replace the piston pin.
- Using a caliper gauge, measure the connecting rod small end bore diameter.
Specification
Standard connecting rod small end bore diameter: 20.012-20.021 mm (0.7879-0.7882 in)
- If the diameter is not as specified, replace the connecting rod.
- Subtract the piston pin diameter measurement from the piston pin bore diameter measurement.
Specification
• | Standard oil clearance: -0.001 to +0.005 mm (-0.00004 to +0.0002 in) |
• | Maximum oil clearance: 0.010 mm (0.0004 in) |
- If the oil clearance is greater than the maximum, replace the connecting rod. If necessary, replace the piston and piston pin as a set.
- Subtract the piston pin diameter measurement from the connecting rod small end bore diameter measurement.
Specification
• | Standard oil clearance: 0.00-0.011 mm (0.0002-0.0004 in) |
• | Maximum oil clearance: 0.014 mm (0.0006 in) |
- If the oil clearance is greater than the maximum, replace the connecting rod. If necessary, replace the connecting rod and piston pin as a set.
- Using a connecting rod aligner and feeler gauge, check the connecting rod alignment.
- Check for misalignment.
Specification
Maximum misalignment: 0.05 mm (0.0020 in) per 100 mm (3.94 in)
- If the misalignment is greater than the maximum, replace the connecting rod.
- Check for twist.
Specification
Maximum twist: 0.15 mm (0.0059 in) per 100 mm (3.94 in)
- If the twist is greater than the maximum, replace the connecting rod.