Removal & Installation
3.5L & 3.7L Engines
Hummer H3 2006-2010
- Remove the camshaft cover.
Rotate the crankshaft until the affected cylinder valve is fully open (cam lobe fully depressing the spring).
NOTEImportant: 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.
Install the EN-47945 on the engine cylinder head using either one or two of the supplied fasteners installed in the coil fastener hole.
WARNINGDO 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.
- 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.
- Remove the valve rocker arm and valve lash adjuster.
Clean and inspect the valve rocker arm and valve lash adjuster.
- Lubricate the valve rocker arm and fill the valve lash adjuster with oil.
- Install the valve rocker arm and valve lash adjuster.
- 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.
- Remove the EN-47945 from the cylinder head and repeat as required.
- Install the camshaft cover.
Hummer H3 2006-2010
Remove the rocker arm cover.
NOTEThe engine firing order is 1, 8, 7, 2, 6, 5, 4, 3. Cylinders 1, 3, 5 and 7 are the left bank.
Remove the number one cylinder spark plug.
NOTEPlace the rocker arms, pushrods, and pivot support, in a rack so that they can be installed in the same location from which they were removed.
- Remove the rocker arm bolts.
Remove the rocker arms.
Remove the rocker arm pivot support.
- Remove the pushrods.
Clean and inspect the rocker arms and pushrods, if required.
When reusing the valve train components, always install the components to the original location and position.
- Valve lash is net build, no valve adjustment is required.
- Lubricate the rocker arms and pushrods with clean engine oil.
- Lubricate the flange of the rocker arm bolts with clean engine oil. Lubricate the flange or washer surface of the bolt that will contact the rocker arm.
Install the rocker arm pivot support.
NOTEMake sure that the pushrods seat properly to the valve lifter sockets.
Install the pushrods.
NOTEMake sure that the pushrods seat properly to the ends of the rocker arms. DO NOT tighten the rocker arm bolts at this time.
Install the rocker arms and bolts.
NOTEThe engine firing order is 1, 8, 7, 2, 6, 5, 4, 3. Cylinders 1, 3, 5 and 7 are the left bank. Cylinders 2, 4, 6 and 8 are the right bank.
- Rotate the crankshaft until the number one piston is at top dead center (TDC) of the compression stroke. In this position, the number one cylinder rocker arms will be off lobe lift.
With the engine in the number one firing position, tighten the following rocker arm bolts:
Tighten cylinders 1,2,7 and 8 exhaust valve rocker arm bolts to 22 ft. lbs. (30 Nm).
- Rotate the crankshaft 360 degrees.
Tighten the following rocker arm bolts:
Tighten cylinders 3, 4, 5 and 6 exhaust valve rocker arm bolts to 22 ft. lbs. (30 Nm).
- Install the number one cylinder spark plug.
- Install the rocker arm cover.