100—ELECTRICAL SYSTEM CHRYSLER SERVICE MANUAL
b.
Testing Armature for Ground
Touch armature shaft and end of a commutator
bar with pair of test lamp test prods. If lamp
lights, it indicates a grounded armature. Re-
place grounded armature.
c. Testing Commutator Run-Out,
Refacing and Undercutting
Place armature in pair of "Vee" blocks and
check runout with dial indicator. Check both
shaft and commutator. A bent shaft requires
replacement of armature. When commutator
runout exceeds .003 inch, commutator should
be refaced. Remove only sufficient metal to pro-
vide a smooth, even surface. After commutator
is refaced, undercut insulation between bars to
depth of Ys2 inch with a thin, hacksaw blade,
or Tool C-770. Undercut insulation square and
full width of groove, and polish commutator
with 00 sandpaper to remove burrs.
10.
TESTING THE BRUSH HOLDERS AND
FIELD COILS FOR GROUND
Touch each of brush holders with a test lamp
prod, while holding the other test prod against
starter frame. Two of brush holders that are
180 degrees apart should cause test lamp to
light, as they are intentionally grounded. The
other two brush holders should not cause lamp
to light when tested, as they are insulated. If
these insulated brush holders cause lamp to
light when tested, it indicates that brush hold-
ers or field coil are grounded. Be sure brush
pigtails or leads are not touching field frame.
Remove screws from field-coil-to-brush-hold-
er leads and insulate leads from brush holders.
Retest by first touching holders and then field
coil leads. If field coils are grounded, inspect
terminal insulation. If insulation is in good
condition, test each coil separately after un-
soldering connection wire. Replace grounded
field
coils.
If brush holders are grounded, re-
place frame and brush holder assembly.
11.
REPLACING THE FIELD COILS
A pole shoe screwdriver should be used to re-
move and install field coils to prevent damage
to pole shoe screws and for proper tightening.
Pole shoes that are loose may cause armature
core to rub pole shoes. This will decrease starter
efficiency and damage the armature core.
12.
SERVICING THE BUSHINGS
Inspect armature shaft bearing surfaces and
bearings for wear by placing core in vise
equipped with soft jaws. Do not squeeze tightly.
Try commutator end frame, the drive end
frame, and armature support bearings for wear
by placing them on shafts and checking for side
play. Replace commutator end frame assembly
if bearing is worn. Also, replace drive end bear-
ing if it is worn. The bearing should be well
soaked in SAE 10-W Engine Oil before it is
installed.
13.
SERVICING THE DRIVE UNIT
Place drive unit on shaft and, while holding
armature, rotate pinion. The drive pinion should
rotate smoothly in one direction (not necessarily
easily), but should not rotate in opposite di-
rection. If drive unit does not function proper-
ly or pinion is worn or burred, replace drive
unit.
14.
ASSEMBLING THE STARTER
(Refer to Figure 4.) Assemble drive end parts
on armature and slide assembly into field frame
until end of commutator touches brushes. While
holding armature against brushes with slight
pressure, push brushes up and allow them to
come to rest on commutator. When all brushes
are seated on commutator, slide armature as-
sembly into place. Install commutator end
frames and through bolts. Make sure end
frames are positioned on dowel pins, and tight-
en through bolts. Install solenoid switch assem-
FEELER
Fig.
5—Adjusting Starter Drive Pinion Clearance
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