F 350 2WD Pickup V8-460 7.5L VIN G EFI (1997)
Starter Armature: Testing and Inspection
ARMATURE
Cleaning
CAUTION: Do not wash the starter drive because the solvent will wash out the lubricant and cause the starter drive to slip.
Wipe field coils, armature, commutator and armature shaft with a clean cloth. Wash springs, shims, thrust washer, trip collar, locking collar
and brush end housing assembly in solvent, and dry the parts.
Inspection
1. Inspect armature for broken or burned insulation and unsoldered connections. Inspect commutator surface for grooves, and check for
runout.
2. If surface of commutator is rough or more than 0.051 mm (0.002 inch) out of round, turn it down. Do not undercut the mica.
3. Inspect for gear teeth that are broken or that show evidence of step wear or root interference.
4. Check armature as follows for shorts, opens or grounds, using suitable test equipment and instruments (test lamp must be 110 volts or
less):
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Rotate armature in a growler, holding a steel strip, such as a hacksaw blade, against the armature. If a short circuit is present, the steel
strip will vibrate in that area.
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Check the armature for grounds, using a test lamp or ohmmeter. There must be no continuity between the armature shaft and any point
on the commutator.
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Check for opens by visually inspecting the points where the armature conductors join the commutator. A poor connection often will be
indicated by signs of arcing or burning of the commutator.
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Replace armatures that are shorted, grounded or show evidence of opens.
FIELD COIL INSPECTION
Check field coil windings with a growler lamp for shorts to housing or pole shoes. Connect one growler lamp lead to starter motor housing.
Connect other growler lead to each field coil brush lead, in turn. A short circuit will light growler lamp.
