Chevrolet Silverado / GMC Sierra. Service manual — part 611

1. The markings on the gasket are as follows:

Grade A (1)

Grade B (2)

Grade C (3)

Block over-bored 0.010-0.030 in (0.254-0.762 mm) (4)

Block over-bored 0.010-0.030 in (0.254-0.762 mm) and deck milled 0.008 in (0.203
mm) (5)

2. Install the left cylinder head gasket of the correct grade. The left and right cylinder head

gaskets are not interchangeable. Refer to Cylinder Head Gasket Selection.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 120: View Of Left Cylinder Head Gasket
Courtesy of GENERAL MOTORS CORP.

3. Install the left cylinder head.

Fig. 121: Cylinder Head Bolt Tightening Sequence
Courtesy of GENERAL MOTORS CORP.

4. Install the NEW M12 cylinder head bolts.

NOTE:

This component uses bolts with a preapplied molybdenum
disulfide coating for thread lubrication. Do not remove the
coating or use any additional lubricant. Improperly lubricated
threads will adversely affect the bolt torque and clamp load.
Improper bolt torque and clamp load can lead to engine
damage.

NOTE:

Refer to Fastener Notice .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Tighten the M12 cylinder head bolts in three steps:

Tighten:

1. 1st step 50 N.m (37 lb ft)

2. 2nd step 80 N.m (59 lb ft)

3. 3rd step tighten 60 degrees using J 45059

4. 4th step tighten 60 degrees using J 45059

5. Reuse the M8 bolts. Install the M8 bolts.

Tighten: Tighten the M8 cylinder head bolts to 25 N.m (18 lb ft).

CYLINDER HEAD INSTALLATION - RIGHT SIDE

Tools Required

J 45059 Angle Meter

Installation

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 122: View Of Cylinder Head Gasket Markings
Courtesy of GENERAL MOTORS CORP.

NOTE:

The left and right cylinder head gaskets are not
interchangeable. Improper placement of the cylinder head
gasket will block coolant and oil passages. Blocked coolant
and oil passages will cause severe engine damage.

IMPORTANT: The stamped letter, R or L, must face up. R is the right bank,

L is the left bank.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado