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Valve Spring

  1. Check the valve spring for damage and deformation.
  2. Using a caliper gauge and valve spring tester, check the valve spring free length (reference) and tension/spring height. If it is not within the standard, replace the valve spring.
    NOTE:
    • Measurement should be performed at a temperature of 20°C (68°F).
    • Valve spring free length is described as a reference. If only valve spring free length is out of the standard, it is not necessary to replace the valve spring.

    Valve spring free length (reference): 

    Standard 

    42.64 mm (1.6787 in)

    Valve spring tension/spring height: 

    Set 

    Standard 

    182 - 210 N (18.56 - 21.41 kgf, 40.92 - 47.22 lbf)/33.0 mm (1.2992 in)

    Lift 

    Standard 

    475 - 525 N (48.43 - 53.53 kgf, 106.80 - 118.04 lbf)/22.0 mm (0.8661 in)

  3. Using thickness gauge, surface plate and try square, check the squareness of the valve spring. If it is not within the standard, replace the valve spring.
    NOTE: Measurement should be performed at a temperature of 20°C (68°F).
    1. Place the valve spring on the surface plate, with smaller diameter end facing up.
    2. Using try square and thickness gauge, measure the clearance at the point of 30 mm (1.1811 in) from the bottom, between one coil and the square.

      Valve spring squareness (at height of 30 mm (1.1811 in)): 

      Standard 

      2.5 °, 1.4 mm (0.0551 in) or less

      G13862734Courtesy of SUBARU OF AMERICA, INC.