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SERIES 638 STARTER

The starter is bolted to the flywheel housing. See Figure 27961 . ‪

1.Flywheel ‪

3.Ring Gear ‪

2.Flywheel Housing ‪

4.Starter ‪

Starter Location

NOTICE:

To prevent excessive overrun and damage to the drive and armature windings, the switch should be opened immediately when the engine starts. A cranking period should not exceed 30 seconds without stopping to allow the motor to cool for at least two minutes. ‪

When the cranking circuit is closed, a drive pinion on the armature shaft engages with the teeth on the engine flywheel ring gear to crank the engine. When the engine starts, it is necessary to disengage the drive pinion to prevent the armature from overspeeding and damaging the cranking motor. To accomplish this, the cranking motor is equipped with an overrunning clutch within the drive pinion. The cranking motor drive pinion and the engine flywheel ring gear must be matched to provide positive engagement and to avoid clashing of the gear teeth. ‪

The cranking circuit may contain a key start switch or push switch (or both), a relay, magnetic switches, solenoids, oil pressure switch, fuel pressure switch, and other protective devices. For the complete cranking circuit, refer to the vehicle manufacturer's wiring diagram. ‪

A basic cranking circuit is shown in the following illustration. See Figure 20538 . ‪

Basic Cranking Circuit

A solenoid, mounted on the cranking motor housing, operates the overrunning clutch drive by linkage and a shift lever. When the start switch is closed, the magnetic switch contacts close, and the solenoid windings are connected to the battery. The resulting plunger and shift lever movement causes the pinion to engage the engine flywheel ring gear and the solenoid main contacts to close, and the cranking takes place. ‪

Removal of Starter

Remove the starter as follows: ‪

With the exception of the ECM system, never attempt to service any engine electrical systems until the batteries have been disconnected. When working on the alternator, be careful not to come in contact with the exhaust manifold or turbocharger. These components may be hot. ‪

  1. Remove the ground strap or negative cable(s) from the battery(s).
  2. Tag each lead to ensure correct connections when the starter is reinstalled.
  3. Disconnect the starter cables and solenoid wiring.
  4. Support the starter, and remove the two bolts which secure it to the flywheel housing.
  5. Pull the starter out to remove it from the flywheel housing.
Inspection of Starter

Inspect the starter as follows: ‪

  1. Visually check the solenoid for dust, oil, moisture, and foreign material.
    1. If dust, oil, moisture, and foreign material are present, clean and reuse the starter. Refer to section .
    2. If dust, oil, moisture, and foreign material are not present, reuse the starter. Refer to section .
  2. Visually check the starter for any damage.
    1. If damage is found, replace the starter. Refer to section .
    2. If no damage is found, reuse the starter. Refer to section .

Installation of Starter

Install the starter as follows: ‪

With the exception of the ECM system, never attempt to service any engine electrical systems until the batteries have been disconnected. When working on the alternator, be careful not to come in contact with the exhaust manifold or turbocharger. These components may be hot. ‪

  1. Place starter into the flywheel housing.
  2. Support the starter, and secure it to the flywheel housing with two bolts.
  3. Connect the starter cables and solenoid wiring.
  4. Install the ground strap or negative cable(s) to the battery.