Hummer H3. Manual — part 345

1. The crankshaft sprocket

2. The left balance sprocket

3. The right balance sprocket

Installation Procedure

Fig. 231: View Of Balance Shaft Drive Chain
Courtesy of GENERAL MOTORS CORP.

1. Install the balance shaft drive chain to the following:

1. The left balance sprocket

IMPORTANT: Ensure the darkened links are facing outward.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

2. The right balance sprocket

3. The crankshaft sprocket

Fig. 232: View Of Sprocket Timing Marks
Courtesy of GENERAL MOTORS CORP.

2. Verify the correct timing chain and timing mark alignments:

The left hand balance shaft sprocket timing mark (1) is at the 12:00 position.

The right hand balance shaft sprocket timing mark (2) is at the 2:30 position.

The crankshaft sprocket timing mark (3) is at the 4:30 position.

The 3 timing marks (1-3) on the sprockets line up with a dark link on the chain.

3. Install the balance shaft chain tensioner. Refer to Balance Shaft Chain Tensioner

Replacement.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

BALANCE SHAFT REPLACEMENT - LEFT SIDE

Removal Procedure

1. Remove the balance shaft drive chain. Refer to Balance Shaft Drive Chain Replacement.

Fig. 233: View Of Balance Shafts
Courtesy of GENERAL MOTORS CORP.

2. Remove and discard the left balance shaft bolt.

3. Remove the left balance shaft.

Installation Procedure

IMPORTANT:

Do not disassemble the balance shaft. Remove and
install the balance shaft as a complete assembly.

Rotate the balance shaft to check for free rotation. If the
balance shaft does not turn free, inspect the balance
shaft bearings and bearing surface for damage.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 234: View Of Balance Shafts
Courtesy of GENERAL MOTORS CORP.

1. Lubricate the balance shaft bearing journals with clean engine oil.

2. Install the left balance shaft with the counterweight down to prevent damage to the balance

shaft bearings.

3. Install a NEW balance shaft bolt.

Tighten: Tighten the bolt to 12 N.m (106 lb in).

4. Install the balance shaft drive chain. Refer to Balance Shaft Drive Chain Replacement.

BALANCE SHAFT REPLACEMENT - RIGHT SIDE

Removal Procedure

1. Remove the balance shaft drive chain. Refer to Balance Shaft Drive Chain Replacement.

NOTE:

Refer to Fastener Notice .

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3