Hummer H2. Manual - part 1855

Fig. 583: Engine Block Rear Oil Gallery Plug
Courtesy of GENERAL MOTORS CORP. 

11. Inspect the engine block rear oil gallery plug and O-ring seal. If the O-ring seal on the plug is not cut or 

damaged, the rear oil gallery plug may be used again.  

12. Lubricate the O-ring seal with clean engine oil.  

13. Install the block rear oil gallery plug into the oil gallery bore. A properly installed block plug will 

protrude 0.8-1.4 mm (0.0315-0.055 in) beyond the rear face of the block. 

Fig. 584: Engine Block Front Oil Gallery Plug 
Courtesy of GENERAL MOTORS CORP. 

IMPORTANT: The engine block front oil gallery plug should not be removed unless 

service is required.

 

2004 Hummer H2 

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

  

14. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) to the sides of the NEW front oil gallery 

plug.  

15. Install a NEW engine block front oil gallery plug, if required. Install the front oil gallery plug into the oil 

gallery bore 2.2-2.8 mm (0.0086-0.011 in) below flush. 

Fig. 585: Oil Pressure Sensor & J 41712 
Courtesy of GENERAL MOTORS CORP. 

16. Apply sealant to the threads of the oil pressure sensor.  

17. Use the J 41712 or equivalent in order to install the oil pressure sensor. 

Tighten: Tighten the oil pressure sensor to 20 N.m (15 lb ft).

 

2004 Hummer H2 

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

  

CRANKSHAFT AND BEARINGS INSTALLATION

Tools Required 

J 45059 Angle Meter. See Special Tools and Equipment . 

Fig. 586: Crankshaft Bearings & Bearing Caps 
Courtesy of GENERAL MOTORS CORP. 

 

2004 Hummer H2 

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

  

1. Install the crankshaft thrust bearings to the engine block and center bearing cap.  

2. Install the remaining crankshaft bearings to the engine block and bearing caps.  

3. Lubricate the bearing surfaces and crankshaft journals with clean engine oil. 

IMPORTANT:

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Crankshaft bearing clearances are critical. Excessive crankshaft 
bearing clearance may effect crankshaft position (CKP) sensor 
signals and/or On-Board Diagnostics (OBD) II system performance.  

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Crankshaft bearing caps must be installed to the proper location and 
direction.  

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When installing the crankshaft bearings, align the locating tabs on 
the bearings with the locating notches in the engine block journal 
bore and the bearing cap.  

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Always install crankshaft bearings with their machined partner. Do 
not file bearings or mix bearing halves.  

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To prevent engine block oil leakage, install NEW M8 crankshaft 
bearing cap side bolts. 

The crankshaft bearing cap M8 side bolts have a sealant patch 
applied to the bolt flange. 

 

2004 Hummer H2 

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