Dodge Durango

 Service Manual

Starting Systems » Description and operation
Starter motor

DESCRIPTION

The starter motors used for the 4.7L engines are not interchangeable with the starter motors used for the other available engines for this model. The starter motors used for all 5.2L and 5.9L engines available in this model are interchangeable.

The 4.7L engine starter motor is mounted with two screws to the automatic transmission torque converter housing on the left side of the engine. The starter motors for all of the remaining engines are mounted with one screw, a stud and a nut to the automatic transmission torque converter housing and are also located on the left side of the engine.

Each of these starter motors incorporates several of the same features to create a reliable, efficient, compact, lightweight and powerful unit. The electric motors of both starters have four brushes contacting the motor commutator. These starter motors use four electromagnetic field coils wound around four pole shoes. The starter motors are rated at 1.4 kilowatts (about 1.9 horsepower) output at 12 volts.

These starter motors are serviced only as a unit with their starter solenoids, and cannot be repaired.

If either component is faulty or damaged, the entire starter motor and starter solenoid unit must be replaced.

OPERATION

These starter motors are equipped with a gear reduction (intermediate transmission) system. The gear reduction system consists of a gear that is integral to the output end of the electric motor armature shaft that is in continual engagement with a larger gear that is splined to the input end of the starter pinion gear shaft. This feature makes it possible to reduce the dimensions of the starter. At the same time, it allows higher armature rotational speed and delivers increased torque through the starter pinion gear to the starter ring gear.

The starter motors for all engines are activated by an integral heavy duty starter solenoid switch mounted to the overrunning clutch housing. This electromechanical switch connects and disconnects the feed of battery voltage to the starter motor and actuates a shift fork that engages and disengages the starter pinion gear with the starter ring gear.

These starter motors use an overrunning clutch and starter pinion gear unit to engage and drive a starter ring gear that is integral to the torque converter or torque converter drive plate mounted on the rear crankshaft flange.

Starting system

Starter motor

Starter relay