Piston Pin Inspection

CAUTION:

If the piston or piston pin is replaced, replace the piston, piston pin and the snap ring as a single component.

Measure the piston pin outer diameter using the micrometer. Measurement positions total eight and are in the X and Y directions, at four points (A, B, C, and D) as shown in the figure.
Standard piston pin outer diameter 20.995-21.000 mm {0.82658-0.82677 in}

Fig 1: Measuring Piston Pin Outer Diameter Using Micrometer
Courtesy of MAZDA MOTORS CORP.
Measure the piston pin hole diameter using the caliper gauge. Measurement positions total eight and are in the X and Y directions, at four points (A, B, C, and D) as shown in the figure.
Standard piston pin hole diameter 21.004-21.008 mm {0.82693-0.82708 in}
Calculate the clearance between the piston pin hole diameter and the piston pin outer diameter.
- If it is not within the specification, replace the piston or the piston pin.
Standard clearance between piston pin hole diameter and piston pin outer diameter 0.004-0.013 mm {0.0002-0.0005 in}

Fig 2: Measuring Piston Pin Hole Diameter Using Caliper Gauge
Courtesy of MAZDA MOTORS CORP.
Measure the inner diameter on the small end of the connecting rod using the caliper gauge in the X and Y directions as shown in the figure.
Standard connecting rod small end inner diameter 21.002-21.013 mm {0.82686-0.82728 in}
Calculate the clearance between the inner diameter on the small end of the connecting rod and the piston pin outer diameter.
- If it is not within the specification, replace the connecting rod or the piston pin.
  
  Fig 3: Measuring Inner Diameter On Small End Of Connecting Rod
  Courtesy of MAZDA MOTORS CORP.
Standard clearance between connecting rod small end inner diameter and piston pin outer diameter 0.002-0.018 mm {0.00008-0.00070 in}