Hummer H3. Manual - part 454

J 44221 Camshaft Holding Tool. See Special Tools.

J 45059 Angle Meter. See Special Tools.

Installation Procedure

Fig. 636: View Of J 44221 Installed On Camshafts
Courtesy of GENERAL MOTORS CORP.

1. Install J 44221 with the camshaft flats up and the number 1 cylinder at top dead center. See

Special Tools. The crankshaft pin should be at 12 o'clock when the number 1 piston is at
top dead center.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

Fig. 637: Installing Timing Chain & Sprockets
Courtesy of GENERAL MOTORS CORP.

2. Compress the tensioner and lock in place.

3. Install the crankshaft sprocket.

4. Install the intake camshaft sprocket into the timing chain.

5. Align the (dark) link of the timing chain with the timing mark on the intake camshaft

sprocket (1).

6. Feed the timing chain down through the opening in the head.

7. Install the timing chain onto the crankshaft sprocket. Align the (dark) link of the timing

chain with the timing mark on the crankshaft sprocket (2).

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

8. Install the intake camshaft sprocket onto the intake camshaft.

Fig. 638: View Of Intake Camshaft Sprocket Washer & Bolt
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: It may be necessary to temporarily remove J 44221 to rotate

and hold the camshaft (hex) to align the pin to the camshaft
sprocket. See Special Tools.

NOTE:

Refer to FASTENER NOTICE .

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3

9. Install the intake camshaft sprocket washer and new bolt.

Tighten:

Tighten the new intake camshaft sprocket bolt the first pass to 20 N.m (15 lb ft).

Use J 45059 to tighten the intake camshaft sprocket bolt the final pass an additional
100 degrees. See Special Tools.

Fig. 639: View Of Exhaust Camshaft Actuator
Courtesy of GENERAL MOTORS CORP.

10. Install the exhaust camshaft actuator into the timing chain.

2007 Hummer H3

2007 ENGINE Engine Mechanical - 3.7L - H3