BOLT 4S7141 - Caterpillar

frequent inspection and replacement of the starting motor may be required for the following conditions:
Operation in harsh environments
Applications that require frequent stops and starts, such as the operation of a fast ferryIf the starting motor fails, the engine may not start in an emergency situation. A scheduled inspection of the starting motor is recommended.The starter motor pinion and the flywheel ring gear must be in good condition in order for the engine to start properly. The engine will not start if the starter motor pinion does not engage the flywheel ring gear. The teeth of the starter motor pinion and the flywheel ring gear can be damaged because of irregular engagement.Inspect the starting motor for proper operation. Listen for grinding when the engine is started. Inspect the teeth of the starter motor pinion and the flywheel ring gear. Look for patterns of wear on the teeth. Look for teeth that are broken or chipped. If damaged teeth are found, the starter motor pinion and the flywheel ring gear must be replaced.Inspect all of the components in the air circuit for the starting motor. Inspect all of the air lines and connections for leaks. Remove the air starting motors for inspection. Overhaul the air starting motors. Refer to the Service Manual or consult your Caterpillar dealer for instructions on removing and on overhauling the air starting motors.