NUT 2430378 - Caterpillar

Electric Starting Motor
When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starting motor removed.
Illustration 1 g01134792
Connection for checking pinion clearance
(1) Ground terminal
(2) Switch terminal
(3) Connector to the motor
Install the solenoid without connector (3) from the MOTOR connections (terminal) on the solenoid to the motor.
Connect a battery, that has the same voltage as the solenoid, to the "SW" terminal (2).
Connect the other side of the battery to connector (3).
For a moment, connect a wire from the solenoid connection (terminal), which is marked "MOTOR", to the ground connection (terminal). The pinion will shift to the crank position and the pinion will stay there until the battery is disconnected. Note: Connecting a wire between solenoid connection (terminal), and the ground connection (terminal) for longer than 2 seconds will damage the solenoid coil.
Illustration 2 g01454593
(A) Pinion clearance
(4) Shaft nut
(5) Pinion
Push the pinion toward the end with the commutator in order to remove free movement.
Pinion clearance (A) must be between 8.3 mm (0.326 inch) and 10.1 mm (0.397 inch).
In order to adjust the pinion clearance, remove the plug and turn the shaft nut (4).
After the adjustment is completed, install the plug over the nut (4) and install connector (3) between the solenoid MOTOR terminal and the starting motor.