Hummer H3. Manual — part 300

8. Install the intake manifold. Refer to Intake Manifold Replacement.

VALVE ROCKER ARM AND VALVE LASH ADJUSTER REPLACEMENT

Tools Required

EN-47945 Valve Spring Compressor

Removal Procedure

1. Remove the camshaft cover. Refer to Camshaft Cover Replacement.

2. Rotate the crankshaft until the affected cylinder valve is fully open (cam lobe fully

depressing the spring).

Fig. 71: Compressing Valve Spring
Courtesy of GENERAL MOTORS CORP.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

3. Install the EN-47945 on the engine cylinder head using either one or two of the supplied

fasteners installed in the coil fastener hole.

4. Rotate the engine clockwise enough to ensure the cam is on the base circle (spring will stay

compressed by the tool).

This will allow the lash adjuster and rocker to be removed.

5. Remove the valve rocker arm and valve lash adjuster.

6. Clean and inspect the valve rocker arm and valve lash adjuster. Refer to Valve Rocker

Arm and Valve Lash Adjuster Cleaning and Inspection.

Installation Procedure

1. Lubricate the valve rocker arm and fill the valve lash adjuster with oil.

2. Install the valve rocker arm and valve lash adjuster.

3. When the valve rocker arm and valve lash adjuster are in place, slowly rotate the engine

counterclockwise enough that the cam lobe fully depresses the spring again.

IMPORTANT: Engine design and packaging does not allow all cylinder

locations to use both fasteners for holding the tool to the
cylinder head. One fastener is sufficient in these locations.

IMPORTANT: DO NOT rotate the engine with the tool installed. It is

possible to damage the valves if they contact the piston.
Rotate the engine enough to come back to the base circle of
the cam.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 72: Compressing Valve Spring
Courtesy of GENERAL MOTORS CORP.

4. Remove the EN-47945 from the cylinder head and repeat as required.

5. Install the camshaft cover. Refer to Camshaft Cover Replacement.

VALVE STEM OIL SEAL AND VALVE SPRING REPLACEMENT

Tools Required

EN 46547 Flywheel Holding Tool. See Special Tools.

J 38820 Valve Stem Seal Installer. See Special Tools.

J 39313 Spark Plug Port Adapter. See Special Tools.

J 43059 Valve Retainer Remover/Installer

J-44228-A Valve Spring Compressor

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Removal Procedure

Fig. 73: View Of Service Slot Plug
Courtesy of GENERAL MOTORS CORP.

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

2. Remove the service slot plug.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3