GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Firefly (Canada) 🢒 Engine 🢒 Engine Mechanical - 1.3L 🢒 Valve Rocker Arm and Shaft Cleaning and Inspection

Rocker Arm Shaft Inspection

Tool Required

J 7872 Magnetic Base Dial Indicator Set


    Object Number: 262371 Size: SH
  1. Place the rocker-arm shaft in two V-Blocks, and use a dial indicator in order to measure the runout of the rocker-arm shaft.

    2. Rocker Arm Shaft Runout
    Maximum Runout = 0.20 mm (0.008 in)

  2. If the measured runout exceeds the specifications, replace the rocker-arm shaft.

Rocker Arm Inspection

    Object Number: 262362 Size: SH
  1. Inspect the tips and the cam-riding face (3) of the rocker arms for excessive wear.
  2. Replace any rocker arm that shows excessive wear.

Rocker Arm--to--Rocker Arm Shaft Clearance Inspection

Tools Required

    • J 26900-5 Vernier Caliper
    • J 26900-2 Outside Micrometer

    Object Number: 262326 Size: SH
  1. Using an outside micrometer, measure the diameter of the rocker-arm shaft.

    2. Standard Rocker Arm Shaft Diameter
    15.969-15.984 mm (0.6287-0.6293 in)

  2. Using a Vernier caliper, measure the inside diameter of the rocker arm.

    3. Standard Rocker Arm Inside Diameter
    15.985-16.005 mm (0.629-0.630 in)

  3. Subtract the rocker arm inside diameter from the rocker-arm shaft outside diameter in order to determine the rocker-arm to rocker-arm shaft clearance.

    4. Standard Rocker Arm-to-Rocker Arm Shaft Clearance
    0.001-0.036 mm (0.0001-0.0014 in)

  4. If the measured clearance exceeds the specifications, replace the rocker arm components as necessary.