Starter Motor: Description and Operation

The PG-260 starter motor, used on supercharged engines (L67), features small permanent magnets mounted inside the field frame and a planetary gear reduction mechanism between the armature and drive. A permanent magnet gear reduction motor is about half the weight and size of a field coil motor having the same cranking performance. The drive housing encloses the shift lever, the shift lever mechanism, and the solenoid plunger to protect them from exposure to dirt, icing conditions, and splash.

Solenoid windings are energized when the ignition switch is turned to the "START" position. The resulting plunger and shift lever movement causes the pinion to engage the engine flywheel ring gear and the solenoid main contact switch to close. Cranking takes place. When the engine starts, pinion overrun protects the armature from excessive speed until the switch is opened. Once the solenoid windings are de-energized, the return spring causes the pinion to disengage. The switch should open immediately when he engine starts, to prevent excessive overrun.