from the core surface. Turn the armature slowly. The strip will become magnetized and vibrate if the
armature is shorted. If a short is present, inspect the commutator risers and bars for solder or copper
chips which will short out between the bars. Remove solder or chips. If the short cannot be found,
replace the armature.
(2) Test the armature for ground with a probe. Touch one test probe to the armature shaft and one test
probe to each commutator segment in turn. A lighted probe lamp indicates a ground. Do not touch
probes to bearing or brush areas because an are would burn and damage the smooth surfaces.
Replace armature if grounded.
(3) Test the frame and field for grounds using a test probe. Touch one probe to the terminal and touch
the other probe to an unpainted spot on the frame. The probe lamp will light if a ground is present.
Replace the entire frame assembly, if grounded.
h. Repair.
(1) Solder any armature windings that are loose on the commutator risers. Do not short across the
commutator segments.
(2) Replace any defective or damaged parts such as screws, nuts, springs, and washers.
(3) Replace entire drive assembly if pinion is chipped or corners are worn excessively.
i. Reassembly.
(1) Press the bearing (34, fig. 35) and oil seal (33) into the pinion housing (3).
(2) Press the bearing into the intermediate bearing assembly (7).
(3) Install the thrust washer (25), gasket (28) and intermediate bearing assembly (7) onto the armature
shaft (1).
(4) Insert the woodruff key (22) into the armature shaft (1).
(5) Install the drive head (6), drive spring (5) and drive assembly (4) on to the armature shaft (1).
Position the drive head over the woodruff key. Align the AGO 6571A holes in the drive spring over
the holes in the drive head and drive assembly and secure with special screws (36 and 29) and
lockwashers (30). Bend the lockwashers against screw heads.
(6) Install the thrust washer (21) on the armature shaft (1). Install combined armature, drive units, and
intermediate bearing as an assembly into the pinion housing with screws.
(7) Install the insulating washer, flat washer, lockwashers (18) and nuts (19) on the terminal stud of the
frame and field assembly (37).
(8) Position gasket (28) on pinion housing (3). Install frame and field assembly (37) over armature (1)
and secure against pinion housing with capscrews (32) and lockwashers (31).
(9) Insert felt disk (13) and press bearing intocommutator head assembly (8).
(10) Install the starter motor brushes (14and 15).
(11) Install insulation on inside of the cover band (9). Place the cover band in position on the field and
frame assembly (37) and secure with screw (24) and nut (23).
(12) To measure end play, mount a dial gage on the drive end of the armature shaft. Move the shaft to
its maximum and minimum position of travel of less than 0.006 of an inch minimum. Remove
commutator head assembly (8). Install thrust or spacer washers as needed oncommutator end of
armature shaft until end play is within specified limits.
(13) To measure pinion drive stop clearance, use a thickness gage and measure the distance between
the pinion drive assembly and the inside of the bearing end of the pinion housing. Clearance must
be 1/16 of an inch. If pinion clearance is not as specified, repair starter and install spacer washers
as needed in the commutator end of the armature shaft until pinion drive clearance meets
specifications.
AGO 6871A
75
