Turn the main drive gear by hand to check the internal gears for freedom of rotation.
Visually inspect the gears for cracked or broken teeth.
Visually inspect the bushings for excessive wear or discoloration due to overheating or seizure of the shafts.
Measure the drive shaft end clearance with a dial indicator located at the end of the lubricating oil pump drive
NOTE: If the main drive gear does not turn freely by hand, cracked or broken teeth are found, or the shaft end clearance is not within the specifications given, the oil pump must be replaced or rebuilt. Refer to Lubricating Oil Pump
– Rebuild (07-06).