Cranking System

The SD-255 is a straight drive starter with the pinion driven directly by the armature shaft. Each starter has pole pieces arranged around the armature that are energized by wound field coils. This type of starter is used on the 4.3L and 5.0L gasoline engines.

Solenoid windings are energized when the ignition switch or engine control switch is in the start position. The resulting plunger and shift lever movement causes the pinion to engage the engine flywheel ring gear, the solenoid main contacts to close, and cranking takes place. When the engine starts, the pinion over-running clutch protects the armature from excessive speed until the ignition switch or engine control switch is released, at that time the plunger return spring causes the pinion to disengage. To prevent excessive overrunning, release the ignition switch or engine control switch from the crank position as soon as the engine starts.