G 1500 1/2 Ton Van V8-5.7L VIN R (1997)
Valve: Testing and Inspection
1. Remove the valve rocker arm cover.
2. Rotate the engine one revolution until the mark on the crankshaft balancer lines up with the timing mark on the front cover, and the engine is in the
number one firing position. This may be determined by placing fingers on the number one valve as the mark on the balancer comes near the timing
mark on the front cover. If the valve rocker arms are not moving, the engine is in the number one firing position. If the valve rocker arms move as
the mark comes up to the timing mark, the engine is in the number six firing position. The crankshaft should be rotated 360° or one complete
revolution in order to reach the number one position.
3. With the engine in the number one firing position as determined above, the following valves may be adjusted (Even numbered cylinders are in the
right bank. Odd numbered cylinders are in the left bank)
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Exhaust 1, 3, 4, 8
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Intake 1, 2, 5, 7
4. Back out the adjusting nut until lash is felt at the pushrod then turn in the adjusting nut until all lash is removed. This can be determined by rotating
the pushrod while turning the adjusting nut. When the play has been removed, turn the adjusting nut 360° or one full additional turn in order to
center the valve lifter plunger.
5. Crank the engine one revolution until the timing mark on the front cover and the crankshaft balancer mark are again in alignment. This is the
number six firing position. The following valves may be adjusted
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Exhaust 2, 5, 6, 7
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Intake 3, 4, 6, 8
6. Install the valve rocker arm cover.