SHAFT 9K1749 - 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.
Illustration 2 g01454593
(4) Shaft nut
(5) Pinion
(A) Pinion clearance
Push the pinion toward the end with the commutator in order to remove free movement.
Pinion clearance (A) must be 9.1 mm (0.36 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 the connector (3) between the MOTOR terminal on the solenoid and the starting motor.