GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Yukon - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 Cylinder Head Assemble

Tools Required

J 8062 Valve Spring Compressor


    Object Number: 822537 Size: MH
  1. Clean the cylinder head valve spring seat and/or shim area.

    2. Important: When using the valves and related components again, install the parts to their original location.

  2. Install the valves (9 and 10) into the proper guides. Refer to Separating Parts .

    3. Important: The valve stem oil seal alignment and position on the valve guide is critical.

    An improperly installed valve stem oil seal may lead to excessive oil consumption, increased vehicle emissions, or component damage.

  3. Install the valve stem oil seal and shim assembly (5).
  4. Install the valve spring (4).
  5. Install the valve spring cap (3).

    6. Object Number: 260151 Size: SH
  6. Compress the valve spring using the J 8062 .
  7. Install the valve stem keys.
    8. 7.1. Use grease to hold the keys in place and remove the J 8062 .
    7.2. Make sure the keys seat properly in the groove of the valve stem.
    7.3. Tap the end to the valve stem with a plastic faced hammer to seat the keys, if necessary.

    Object Number: 64315 Size: SH
  8. Measure the valve spring installed height using a ruler. Measure from the base of the spring to the top of the spring.

    9. If the installed height exceeds 46.25 mm (1.82 in), install a valve seat spring shim of approximately 0.5 mm (0.02 in) thick.

    Do not shim the valve spring to obtain less than the specified height.

    Do not assemble the components without a spring shim on the cylinder head, aluminum head.

  9. Install the remaining valves, springs, and other components.

    10. Object Number: 260086 Size: SH
  10. Install sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the threads of the coolant sensor.

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

  11. Install the coolant sensor into the left cylinder head.

    12. Tighten
    Tighten the coolant sensor to 20 N·m (15 lb ft).


    Object Number: 260157 Size: SH
  12. Install the coolant plug to the right cylinder head.

    13. Tighten
    Tighten the coolant plug to 20 N·m (15 lb ft).


    Object Number: 490662 Size: SH
  13. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the sides of the cylinder head expansion plugs (1), if applicable.
  14. Install the expansion plugs into the cylinder head.

    15. A properly installed plug should be installed 2.5 mm (0.1 in) below the end face of the head.