Chevrolet Silverado / GMC Sierra. Manual - part 582
Fig. 15: Measuring Cylinder Head Intake Manifold Deck For Warpage
Courtesy of GENERAL MOTORS CORP.
7. Measure the cylinder head intake manifold deck for warpage. A cylinder head intake
manifold deck with warpage in excess of 0.3 mm (0.011 in) within a 493 mm (19.41 in)
area must be replaced.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 16: Measuring Valve Spring Tension Using J 9666
Courtesy of GENERAL MOTORS CORP.
8. Measure the valve spring tension using J 9666 . Replace the valve spring if the valve spring
tension is less than 315.5 N (7.09 lb) at 41 mm (1.6142 in)
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 17: Measuring Valve Spring For Squareness
Courtesy of GENERAL MOTORS CORP.
9. Measure the valve spring for squareness. Replace the valve spring if squareness is beyond
2.0 mm (0.0787 in).
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 18: Measuring Valve Spring Free Length
Courtesy of GENERAL MOTORS CORP.
10. Measure the valve spring free length. The production free length is 56.6 mm (2.2283 in).
11. Measure the valve stem to guide clearance.
1. Set a dial indicator to the valve stem measuring point.
2. Move the valve stem from side to side while reading the total movement on the dial
indicator. If the measured valve exceeds 0.20 mm (0.0079 in), replace the cylinder
head.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado