GM Service Manual Online
For 1990-2009 cars only

    Object Number: 1240664  Size: SH
  1. Measure the straightness of the rocker arm shaft by using the V block and the dial gage.
  2. Replace the rocker arm shaft if the measured valve is over the specification limit.
  3. Specification
    The specification limit of the rocker arm shaft is 0.10 mm (0.0039 in).


    Object Number: 1240677  Size: SH
  4. Measure the outer diameter of the rocker arm shaft using a micrometer to check the clearance between the rocker arm and the rocker arm shaft.

  5. Object Number: 1240693  Size: SH
  6. Measure the inner diameter of the rocker arm using a bore gage (1).
  7. If the difference is over the limit between the outer diameter and the inner diameter, replace the shaft or the rocker arm, or both if necessary.
  8. Specification
    The limit is 0.005-0.040 mm (0.0002-0.0016 in).