TUBE AS 1509227 - Caterpillar

Illustration 1 g00708701
(1) Timing marks for the fuel injection pump gear (2) Timing marks for the idler gear (3) Timing marks for the camshaft gear (4) Timing mark for the crankshaft gear
Make sure that the marks on the gears are in alignment.
Measure the backlash between the camshaft gear and the idler gear. The backlash between the camshaft gear and the idler gear should be 0.08 mm (0.003 inch).
Measure the backlash between the crankshaft gear and the idler gear. The backlash between the crankshaft gear and the idler gear should be 0.08 mm (0.003 inch).If the backlash is greater than the maximum allowable backlash of 0.25 mm (0.010 inch), replace the gears and measure the backlash again.Timing Of Valves
Illustration 2 g00774292
Cylinder and valve location (A) Exhaust valve (B) Inlet valve (C) Flywheel end of the engine (D) Front of the engine
Remove the valve mechanism cover.
When the engine is viewed from the front, rotate the crankshaft in a clockwise direction until the inlet valve (B) is fully open. The piston for No. 1 cylinder is at top center on the compression stroke.
Set the valve lash of inlet valve (B) to 0.59 mm (0.023 inch).Note: In order to check the valve timing, the valve lash adjustment is increased in Step 3. Loosening the tension on the inlet valve for No. 1 cylinder allows a more accurate determination of the valve lash. The mark on crankshaft pulley (1) should be within 2.5 degrees of the mark on timing case (2). Refer to Step 4.
Illustration 3 g00806495
(1) Crankshaft pulley (2) Mark on Timing case
When the engine is viewed from the front, rotate the crankshaft in a clockwise direction until the pushrod of inlet valve (B) for No. 1 cylinder begins to tighten. In this position, make sure that the mark on crankshaft pulley (1) is within 2.5 degrees of the mark on timing case (2) .Note: Use the following formula to calculate the measurement which is equal to 2.5 degrees on the pulley.(C x P)/360=MC - Circumference of pulleyP - 2.5 degreesM - The linear measurement which is equal to 2.5 degrees on the pulley
If the timing is more than 2.5 degrees out of position, the timing gears are not in correct alignment. Incorrect alignment requires adjustment of the timing of the fuel injection pump. Refer to Testing and Adjusting, "Fuel Injection Timing - Check" .
When the engine is viewed from the front, rotate the crankshaft in a clockwise direction until the inlet valve "B" begins to open and exhaust valve "A" has not completely closed. These valves are in number 4 cylinder. Set the valve lash. Refer to the Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" topic for the correct valve lash.