Hummer H1 (2006+). Manual — part 32

2-34

Engine

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Figure 2-27: Top Dead Center Adjustment Order

3.

Loosen the valve adjusting screws.

4.

Insert a feeler gauge between the tip of the rocker arm and the valve bridge (Figure 2-28).

5.

Adjust the valve lash to 0.012þin. (0.3þmm) and tighten the valve lash lock nut to 16þlb-ft. (22þN·m).

7-E

5-I

3-I

1-E

1-I

8-E

6-I

2-E

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Engine 2-35

5745804

Figure 2-28: Valve Adjusting Screw Adjustment

6.

Rotate the crankshaft one revolution to bring the number 1 cylinder at Top Dead Center of the exhaust stroke.

7.

Refer to (Figure 2-29) to determine which valves that can be adjusted when the engine is at Top Dead Center of the exhaust
stroke.

Figure 2-29: Exhaust Top Dead Center Adjustment Order

3-E

5-E

7-I

8-I

6-E

4-I

4-E

2-I

05-S02-111

2-36

Engine

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8.

Insert a feeler gauge between the tip of the rocker arm and the valve bridge (Figure 2-28).

9.

Adjust the valve lash to 0.012þin. (0.3þmm) and tighten the valve lash lock nut to 16þlbþft (22þN·m).

EXHAUST MANIFOLD SERVICE

The right and left exhaust manifold procedures are very similar in process, this covers the removal of the right side.

Right Exhaust Manifold and Heat Shield Replacement

Removal

1.

Remove the engine access cover.

2.

Remove the four bolts holding the rear heat shield to the right turbo pipe and remove the shield (Figure 2-33).

3.

Remove the four bolts holding the heat shield to the right side exhaust manifold and remove the shield (Figure 2-32).

4.

Remove the three bolts holding the turbo pipe to the exhaust manifold.

5.

Remove the exhaust manifold bolts and nuts in the proper sequence (Figures 2-30, and 2-31).

6.

Remove the exhaust manifold.

7.

Clean and inspect the exhaust manifold for cracks and warpage, if damaged, replace the manifold.

Installation

1.

Install the exhaust manifold nuts and bolts and the turbo pipe to the exhaust manifold bolts finger tight.

2.

Use the sequence shown (Figures 2-30, and 2-31) to properly torque the exhaust manifold bolts/nut to 28þlb-ft. (38þN·m).

3.

Torque the turbo pipe to exhaust manifold bolts to 39þlb-ft. (53þN·m).

4.

Install the heat shields and torque the bolts to 71þlb-in. (8þN·m).

5.

Install the engine access cover.

Figure 2-30: Right Exhaust Manifold Removal and Torque Sequence

5

7

3

4

8

6

2

1

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Engine 2-37

5745804

Figure 2-31: Left Exhaust Manifold Removal and Torque Sequence

Figure 2-32: Right Heat Shield

2

6

3

7

5

1

8

4

HEAT SHIELD

EXHAUST MANIFOLD

CYLINDER HEAD