GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2005 🢒 H2 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 Valve Rocker Arm Cover Replacement - Right Side

Removal Procedure

    Object Number: 1235686 Size: SH
  1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .
  2. Remove the connector position assurance (CPA) lock (5).
  3. Disconnect the main electrical connector (4) feeding the ignition coils.
  4. Remove the harness clips (1).
  5. Reposition the engine harness.
  6. Remove the spark plug wires from the ignition coils.
    7. • Twist each plug wire 1/2 turn.
    • Pull only on the boot in order to remove the wire from the ignition coil.

    Object Number: 688018 Size: SH
  7. Reposition the surge tank/heater hoses from the heater hose bracket.
  8. Remove the heater hose bracket nut and bracket.

    9. Object Number: 647792 Size: SH
  9. Remove the ignition coil bracket studs from the rocker arm cover.
  10. Remove the ignition coils and bracket from the rocker cover.
  11. Remove the positive crankcase ventilation (PCV) fresh air hose.

    12. Object Number: 260084 Size: SH
  12. Remove the valve rocker arm cover bolts.
  13. Remove the valve rocker arm cover.

    14. Object Number: 490696 Size: SH
  14. Remove the gasket (1) from the rocker cover.
  15. Discard the OLD gasket.

    16. Object Number: 647798 Size: SH
  16. Remove the oil fill cap from the oil fill tube.
  17. Remove the oil fill tube from the rocker cover, if required.
  18. Discard the oil fill tube.
  19. Clean and inspect the rocker arm cover. Refer to Valve Rocker Arm Cover Cleaning and Inspection .

Installation Procedure

Important: 

   • All gasket surfaces should be free of oil or other foreign material during assembly.
   • DO NOT reuse the valve rocker arm cover gasket.
   • The valve rocker arm cover bolt grommets may be reused.
   • If the oil fill tube has been removed from the rocker arm cover, install a NEW fill tube during assembly.


    Object Number: 647798 Size: SH
  1. Lubricate the O-ring seal of the NEW oil fill tube with clean engine oil.
  2. Insert the NEW oil fill tube into the rocker arm cover.

    3. Rotate the tube clockwise until locked in the proper position.

  3. Install the oil fill cap into the tube.

    4. Rotate the cap clockwise until locked in the proper position.


    Object Number: 490696 Size: SH
  4. Install a NEW rocker cover gasket (1) into the valve rocker cover lip.

    5. Object Number: 260084 Size: SH
  5. Install the valve rocker arm cover onto the cylinder head.

    6. Notice: Refer to Fastener Notice in the Preface section.

  6. Install new rocker arm cover grommets, if necessary.
  7. Install the rocker arm cover bolts and grommets.

    8. Tighten
    Tighten the bolts to 12 N·m (106 lb in).

  8. Install the PCV fresh air hose.

    9. Object Number: 647792 Size: SH
  9. Apply threadlock to the threads of the bracket bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  10. Install the ignition coils and bracket to the rocker arm cover.
  11. Install the ignition coil bracket studs to the rocker cover.

    12. Tighten
    Tighten the studs to 12 N·m (106 lb in).


    Object Number: 688018 Size: SH
  12. Install the heater hose bracket and nut.

    13. Tighten
    Tighten the nut to 9 N·m (80 lb in).

  13. Position the surge tank/heater hoses to the heater hose bracket.

    14. Object Number: 1235686 Size: SH
  14. Install the spark plug wires to the ignition coils.
  15. Re-position the engine harness.
  16. Install the harness clips (1).
  17. Connect the main electrical connector (4) feeding the ignition coils.
  18. Install the CPA lock (5).
  19. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .