GUARD-IDLER 1395743 - Caterpillar

Illustration 1 g01126079
Front Gear Group
(1) Camshaft gear and timing reference ring
(2) Timing marks
(3) Idler gear
(4) Crankshaft gear The basis for correct fuel injection timing and valve mechanism operation is determined by the notched gear teeth and the alignment of the front gear group. The timing notches are located on one tooth of the cam gear and one tooth of the crank gear. The gear teeth and the notch are used to measure speed and timing.Refer to Disassembly and Assembly, "Gear Group (Front) - Remove" and Disassembly and Assembly, "Gear Group (Front) - Install".Note: If timing reference ring (1) is installed backward the engine will not start.Check for proper alignment of the camshaft gear and timing reference ring (1) on the camshaft assembly. Inspect the key between the timing reference ring and the camshaft gear. Check the teeth on the timing ring. The teeth should not be defaced. The teeth should have sharp clean edges and the teeth should be free of contaminants.Note: The electronic injection timing must be calibrated after reassembly of the front gear train. Refer to Troubleshooting, "Timing - Calibrate".