The P72, equipped with the 6.5L, VIN F diesel engine, uses the 28-MT starter motor. The P92, equipped with the 6.6L, VIN 5 diesel engine, uses the 37-MT starter motor.

The 28-MT uses a gear reduction system in order to drive the pinion.

The 28-MT has a shift lever mechanism. The solenoid plunger is enclosed in the drive housing in order to protect it from exposure to dirt, icy conditions and splash.

The solenoid windings energize when the engine control switch is in START. The resulting plunger and shift lever movement causes the pinion to mesh with the engine flywheel ring gear. The solenoid main contacts close and engine cranking takes place. When the engine starts, the pinion overrunning clutch protects the armature from excessive speed until the ignition switch is released, at which time the plunger return spring causes the pinion to disengage. In order to prevent excessive overrunning, release the engine control switch immediately when the engine starts.

The 37-MT has an adjustable drive end frame housing and oil reservoirs with wicks. It also has an enclosed shift lever. The shift lever mechanism and the solenoid plunger are within the drive housing, protecting them from exposure to dirt, icy conditions and splash.

The solenoid operates when the engine control switch is turned to START. The resulting plunger and shift lever movement causes the pinion to mesh with the engine flywheel ring gear. The solenoid main contacts close and cranking takes place. When the engine starts, the pinion overrunning clutch protects the armature from excessive speed. When the engine control switch is released, the plunger return spring causes the pinion to disengage. In order to prevent excessive overrunning, the key should be released immediately when the engine starts.