Knowing the components of a starter, and what is their function, is a definite plus in trouble shooting and repairing or replacing a faulty starter.

The components of a starter are the front housing or head, the overrunning flywheel and clutch and pinion assembly, the armature, the field coils, the brushes, the brush carrier, the field coil housing, the end cover, the starter solenoid contacts, the starter solenoid spring, the starter solenoid lever, and the starter solenoid.

The front housing or head is dome shaped with a smaller dome attached to it. About forty percent of the larger dome is cut away to allow for the pinion gear to engage the ring gear on the flex plate for automatic transmissions or flywheel for manual transmissions. A hole is machined into the tip of the dome to allow for the front end of the armature shaft to be stabilized. The machined hole will have a tube shaped bushing or roller bearing press fit into it to reduce friction of the spinning armature shaft. On the edge of the large round opening of the dome will be two small threaded holes to allow for the starter through bolts to be screwed into them. The smaller dome attached to the side to the larger dome allows movement of the lever mechanism of the solenoid to engage the pinion gear to the ring gear.

The overrunning clutch and pinion gear assembly consists of the one way clutch, pinion gear, and, depending on design application, return spring. On some applications the return spring is inside the solenoid assembly. The overrunning clutch keeps the pinion gear from spinning on the armature shaft while the starter is cranking the engine. When the engine begins to run the overrunning clutch releases the pinion gear and allows it to spin preventing damage to the ring and pinion gear. When the ignition key is released from the start position, the starter solenoid de-activates allowing the pinion gear to retract from the ring gear into the starter housing. The pinion gear is able to turn the ring gear because of gear ratio. Gear ratio is the relationship between two gears meshing with each other based on the number of teeth on each gear.