GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1996 🢒 Tahoe - 4WD 🢒 Engine 🢒 Engine Mechanical - 6.5L 🢒 Camshaft Gear Timing Test

Important: This procedure is a test for proper camshaft gear timing without removing the engine 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

  1. Remove all of the glow plugs.
  2. Remove the valve rocker arm cover and the valve rocker arms for the number 1 cylinder.
  3. Mount the dial indicator on the exhaust pushrod and zero gauge in order to read the camshaft exhaust lobe lift.

Test Procedure

  1. Slowly rotate the crankshaft clockwise until the dial indicator shows the maximum exhaust lobe lift.
  2. Place a chalk mark on the crankshaft balancer next to the timing tab.
  3. Reposition the dial indicator over the intake pushrod and slowly rotate the crankshaft clockwise until the maximum lobe lift is obtained.
  4. Place a second chalk mark on the crankshaft balancer next to the timing tab.
  5. 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

  1. Install the valve rocker arms and the valve rocker arm cover.
  2. Install all of the glow plugs.