Important: This procedure is a test for proper camshaft gear timing without removing
the front cover of the engine.
The following test will not work with the valve rocker arms on the heads
because the valve spring pressure causes the valve lifters to bleed down and
not give true lobe lift readings. Also, it is important that the crankshaft
lobe is rotated only in a clockwise direction so that the timing chain slack
does not effect the position of the maximum lobe lift.
Removal Procedure
- Remove all of the spark plugs.
- Remove the valve rocker arm cover and the valve rocker arms for
the number 1 cylinder. Mount a dial indicator on the exhaust pushrod and zero
guage in order to read the camshaft exhaust lobe lift.
Test Procedure
- Slowly rotate the crankshaft clockwise until the dial indicator
shows the maximum exhaust lobe lift.
- Place a chalk mark on the crankshaft balancer next to the timing
tab.
- Reposition the dial indicator over the intake pushrod and slowly
rotate the crankshaft clockwise until the maximum lobe lift is obtained.
- Place a second chalk mark on the crankshaft balancer next to the
timing tab.
- Measure the distance from each of the chalk marks to the factory
timing groove in the crankshaft balancer. If the camshaft gear is properly
indexed (positioned) to the crankshaft gear, the distance of each chalk mark
to the factory gear timing groove (TDC) will be roughly the same. If the gears
are out of position by one tooth or more, the distance from the chalk marks
to the (TDC) mark will differ by roughly 50.8 mm (2 in) or more.
Installation Procedure
- Install the valve rocker arms and the valve rocker arm cover.
- Install all of the spark plugs.