Hummer H3. Manual — part 379

Fig. 361: View Of Crankshaft Rear Oil Seal Housing
Courtesy of GENERAL MOTORS CORP.

1. Remove the crankshaft rear oil seal housing and bolts.

2. Install 2 bolts (Jack Screws) into the threaded holes to break the seal of the housing.

3. Remove the crankshaft rear oil seal housing.

CRANKSHAFT REAR OIL SEAL REMOVAL

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 362: View Of Crankshaft Rear Oil Seal
Courtesy of GENERAL MOTORS CORP.

Remove the crankshaft rear oil seal and discard.

BALANCE SHAFT REMOVAL

IMPORTANT: Do not damage the crankshaft or seal bore. Pry out the crankshaft

rear oil seal out using a suitable tool.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 363: Sprocket Timing Marks
Courtesy of GENERAL MOTORS CORP.

1. Rotate the crankshaft until the left hand balance shaft sprocket timing mark is at 12:00. The

right hand balance shaft sprocket timing mark should be at 2:30. The crankshaft sprocket
timing mark should be at 4:30. Make sure the 3 timing marks on the sprockets line up with a
dark link on the chain (1). Every 11-crankshaft rotations, 3 of the 5 dark links on the timing
chain will line up with the timing marks.

IMPORTANT: Do not disassemble the balance shaft assembles. Remove

and install the balance shafts as complete assemblies.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 364: View Of Balance Shaft Chain Tensioner
Courtesy of GENERAL MOTORS CORP.

2. Remove the balance shaft chain tensioner and bolts.

IMPORTANT: It may be necessary to retract the tensioner plunger by

rotating the link plate clockwise. Insert a small tool into the
link plate hole in order to prevent the tensioner from
ratcheting to full extension.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3