Cleaning, Inspection and Testing

Testing Field For Open:

Testing Field For Ground:

Testing Solenoid Winding:

1. Clean all starting motor parts, but DO NOT USE GREASE DISSOLVING SOLVENTS FOR CLEANING. Solvent would dissolve the grease packed in the clutch and would damage armature and field coil insulation. Wipe parts with a clean shop cloth.
2. Test drive assembly action. The pinion should turn freely in the overrunning direction. Check pinion teeth to see that they have not been chipped, cracked, or excessively worn. Replace assembly if necessary. Badly chipped pinion teeth may indicate chipped teeth on the ring gear, which should be replaced if necessary.
3. Check the drive assembly for slipping by leaving the assembly attached to the armature, wrap the armature with a shop towel and clamp the armature in a vise. Using a 12-point deep socket and torque wrench, put the socket on the pinion and turn counterclockwise. The drive should not slip up to 68 N.m (50 lb. ft.). of torque. If it does, replace the drive assembly.
4. The roll type drive assembly should be wiped clean. DO NOT clean in any degreasing tank, or with grease dissolving solvents; this will dissolve the lubricant in the drive mechanism.
5. Inspect armature commutator. If commutator is dirty, clean with 400 grit polishing cloth then wipe clean. If commutator is rough, the armature should be replaced. Do not undercut or turn commutators. Inspect the points where the armature conductors join the commutator bars to make sure they have a good connection. A burned commutator bar is usually evidence of a poor connection.
6. If test equipment is available:
A. Check the armature for short circuits by placing on growler and holding back saw blade over armature core while armature is rotated. If saw blade vibrates, armature is shorted. Recheck after cleaning between the commutator bars. If saw blade still vibrates, replace the armature.
B. Check frame and field assembly by using a test lamp, place one lead on the field lead terminal and the other lead on one insulated brush. If the lamp fails to light, the series coil is open and will require repair or replacement. This test should be made from each insulated brush to check brush and lead continuity.
C. Using a test lamp place one lead on the grounded brush holder and the other lead on either insulated brush. If the lamp lights, a grounded series coil is indicated and must be repaired or replaced.
D. Check the current draw of the solenoid winding as follows:
- If solenoid is not removed from starter motor, the field lead must be removed from the terminal on the solenoid before making these tests. Complete tests in a minimum of time to prevent overheating of the solenoid.
- To check hold-in winding, connect an ammeter in series with 12-volt battery and the "switch" terminal on the solenoid. Connect a voltmeter to the "switch" terminal and to ground. Connect carbon pile across battery. Adjust the voltage to 10 volts and note the ammeter reading.
- Readings should be 10 to 20 amperes. To check both windings, connect the same as for the previous test. Ground the solenoid motor terminal. Adjust the voltage to 10 volts and note the ammeter reading. It should be 60 to 85 amperes.

- NOTE: Current will decrease as windings heat up.

- Current draw readings that are over specifications indicate shorted turns or a ground in the windings of the solenoid and the solenoid should be replaced. Current draw readings that are under specifications indicate excessive resistance. A zero reading indicates an open circuit. Check connections then replace solenoid if necessary.
7. Starter solenoid switch is serviced as an assembly.