Hummer H2. Manual - part 1837

Fig. 517: Crankshaft Rear Oil Seal
Courtesy of GENERAL MOTORS CORP.

1. Remove the crankshaft oil seal (141) from the rear cover.

2. Clean the cover in solvent. Remove the sealant from the cover oil pan surface. Refer to Replacing

Engine Gaskets .

IMPORTANT:

Do not use the crankshaft oil seal again. Install a NEW crankshaft oil
seal during assembly.

Do not use the rear cover-to-engine block gasket again. Install a
NEW gasket during assembly.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

3. Dry the cover with compressed air.

4. Inspect the gasket sealing surfaces for excessive scratches or gouging.

5. Inspect the cover-to-oil pan threaded bolt holes for damaged threads or debris.

6. Inspect the crankshaft oil seal mounting bore for damage.

ENGINE VALLEY COVER CLEANING AND INSPECTION

Fig. 518: Knock Sensor Oil Seals & Valley Cover
Courtesy of GENERAL MOTORS CORP.

1. Remove the knock sensor oil seals (520) from the valley cover (555).

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

IMPORTANT:

Do not use the valley cover knock sensor oil seals again. Install
NEW oil seals during assembly.

Do not use the valley cover gasket again. Install a NEW gasket
during assembly.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

2. Clean the valley cover in solvent.

3. Dry the valley cover with compressed air.

4. Inspect the gasket sealing surfaces for excessive scratches or gouging. Refer to Replacing Engine

Gaskets .

5. Inspect the valley cover oil seal bores for excessive scratches or gouging.

VALVE ROCKER ARM COVER CLEANING AND INSPECTION

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 519: Ignition Coil & Bracket Assembly (Left)
Courtesy of GENERAL MOTORS CORP.

IMPORTANT:

Do not use the valve rocker arm cover gasket again. Install a NEW
gasket during assembly.

Remove the ignition coils before cleaning the cover in solvent. Do
not submerge the ignition coils in solvent.

Do not remove the oil fill tube or crankcase vent valve grommet from
the covers unless service is required.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2