Chevrolet Silverado / GMC Sierra. Service manual — part 454

11. Tighten the rocker arm shaft bolts in the sequence shown.

Tighten: Tighten the bolts to 41 N.m (30 lb ft).

12. Adjust the valve clearance. Refer to Valve Lash Adjustment .

13. Install the lower valve rocker arm covers. Refer to Valve Rocker Arm Cover

Replacement - Lower Left Side or Valve Rocker Arm Cover Replacement - Lower
Right Side.

VALVE CLEARANCE ADJUSTMENT

2008 Chevrolet Silverado 1500

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

Fig. 138: View Of Crankshaft Balancer Mark Aligned With Engine Mark
Courtesy of GENERAL MOTORS CORP.

1. Remove the fan clutch. Refer to Fan Clutch Replacement (Diesel) .

2. Remove the upper valve rocker arm covers. Refer to Valve Rocker Arm Cover

Replacement - Upper Left Side and Valve Rocker Arm Cover Replacement - Upper
Right Side.

2008 Chevrolet Silverado 1500

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

3. Rotate the crankshaft in order to bring the number 1 cylinder to top dead center (TDC) of

the compression stroke. The number 1 cylinder is the front cylinder on the right bank. The
mark on the crankshaft balancer should be aligned with the mark on the engine.

Fig. 139: View Of Feeler Gage Between Tip Of Rocker Arm & Valve Lifter Bridge
Courtesy of GENERAL MOTORS CORP.

4. Loosen the valve adjusting screws.

5. Insert a feeler gage between the tip of the rocker arm and the valve bridge.

2008 Chevrolet Silverado 1500

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

Fig. 140: View Of Rocker Arm Intake & Exhaust Valves 1, 2, 3, 5, 6, 7 & 8
Courtesy of GENERAL MOTORS CORP.

6. Adjust the valve lash to 0.3 mm (0.012 in). Refer to Valve Clearance Adjustment

Specifications to determine which valves can be adjusted when the engine is at TDC.

NOTE:

Refer to Fastener Notice .

2008 Chevrolet Silverado 1500

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