PISTON INSPECTION

id011000502100

  Caution
  • The piston, piston pin and connecting rod (semi-floating type piston pin) cannot be disassembled.
  • When replacing the piston, piston pin, and connecting rod (semi-floating type piston pin), replace them together as a single unit.
  • If the piston, piston pin, and connecting rod of the full floating type piston pin are disassembled, the piston, piston pin, and snap ring must be replaced as a single unit.

1. Measure the outer diameter of each piston at right angle 90° to the piston pin, 10.0 mm {0.40 in} above the under of the piston.

  Semi-floating type piston pin

  • If not within the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.

  Full floating type piston pin

  • If not within the specification, replace the piston, piston pin and snap ring as a single unit.

belbze00000105

  Piston diameter

  L8: 82.965—82.995 mm {3.2664—3.2675 in}
  LF, L3: 87.465—87.495 mm {3.4435—3.4446 in}
  L5: 88.965—88.995 mm {3.5026—3.5037 in}

2. Measure the piston-to-cylinder clearance.

  Semi-floating type piston pin

  • If not within the specification, replace the piston, piston pin, piston ring and connecting rod as a single unit.

  Full floating type piston pin

  • If not within the specification, replace the piston, piston pin and snap ring as a single unit.

  Standard clearance

  0.025—0.045 mm {0.0010—0.0017 in}

  Maximum clearance

  0.11 mm {0.0043 in}

3. Measure the piston ring-to-ring groove clearance around the entire circumference.

  • If it exceeds the specification, replace the piston and piston ring.

belbze00000106

  Standard clearance

  Top: 0.04—0.08 mm {0.0016—0.0031 in}
  Second: 0.03—0.07 mm {0.0012—0.0027 in}
  Oil: 0.06—0.15 mm {0.0024—0.0059 in}

  Maximum clearance

  Top: 0.17 mm {0.0067 in}
  Second, Oil: 0.15 mm {0.0059 in}

4. After inserting the piston ring into the cylinder, press in the piston ring to the position 42 mm {1.65 in} from the cylinder surface using the piston.

5. Measure each piston ring end gap with a feeler gauge.

  • If it exceeds the specification, replace the piston ring.

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  Standard end gap

  Top
  L8: 0.15—0.30 mm {0.006—0.011 in}
  LF, L3: 0.16—0.31 mm {0.007—0.012 in}
  L5: 0.16—0.26 mm {0.0063—0.010 in}
  Second
  L8: 0.32—0.47 mm {0.013—0.018 in}
  LF, L3: 0.33—0.48 mm {0.013—0.018 in}
  L5: 0.31—0.46 mm {0.013—0.018 in}
  Oil (rail)
  L5: 0.15—0.40 mm {0.006—0.015 in}
  Except L5: 0.20—0.70 mm {0.0079—0.0275 in}

  Maximum end gap

  1.0 mm {0.0393 in}