STARTING MOTOR REPAIR AND REPLACEMENT.

TM 55-4920-335-14

Disassembly.

Removal.

(1) Remove two thru bolts and remove frame from

(1) Disconnect electrical lead to starting motor.

brush end. Lift brush arms and pull brushes out of holders.

(2) Remove one screw and lockwasher securing

(2) Pull armature with parts attached out of generator

starting motor to support bracket.

field. Disassemble pulley, frame, and fan from armature shaft.

(3) Remove three screws and lockwashers securing

Remove bearing retainer and gasket from frame.

flange of starting motor to engine and remove starting motor.

Inspection and Repair.

Disassembly.

(1) Examine ball bearing in end frame and replace if

(1) Remove cover band from body of motor. Pull

worn.

brushes from brusholder.

(2) Test armature for shorts and repair or replace as

(2) Remove four screws and lock washers attaching

required.

commutator end head to body of motor and remove head.

(3) Examine commutator and turn down in a lathe if

(3) Detach pinion housing from body of motor by

required.

removing four screws and lock washers and loosening head

(4) Examine brushes for excessive wear, frayed

screw in drive head of bendix drive assembly and pull

pigtails, and shorts.

assembly off shaft of armature.

(5) Remove screw and lock washers holding pigtail

(4) Remove four screws and pull intermediate

of each brush and remove brush. Install new brush by

bearing plate assembly out of pinion housing. Pull armature

attaching pigtail with screw and lockwasher.

out of body.

(6) When installing new brushes, place brush in

holder and insert armature into position. Place a strip of No.

Inspection and Repair.

00 sandpaper under the brushes with sand side out, hold

sandpaper to conform to contour of commutator. Move

(1) Examine armature and test for ground. Repair

sandpaper together with armature back and forth under brush.

grounded armature if possible, otherwise replace. Clean a

After a few oscillations, examine brush; it should make at least

burned, dirty, or oily commutator with No. 00 sandpaper.

75 percent contact with commutator.

Repeat sanding

Examine commutator for high mica and turn down in lathe if

procedure if necessary.

necessary.

(2) Check brush spring tension, and condition of

Reassembly.

brushes. Replace with new parts. Fit brushes to commutator

with sandpaper.

(1) Install ball bearing retai ner and gasket on end

(3) Examine bearings for wear and replace

frame.

excessively worn parts.

(2) Install end frame, fan, and pulley onto armature

shaft.

Reassembly.

(3) Insert assembled armature into field housing.

Insert brushes in brusholders.

(1) Install intermediate bearing plate with hub end

(4) Install brush end frame and secure entire

toward armature, and bendix drive parts onto shaft of

assembly with two thru bolts and washers.

armature. Attach intermediate bearing plate to pin on housing

with four screws and lock washers.

Installation.

(2) Install armature and pinion housing assembly in

body of motor. Attach pinion housing to body with four screws

(1) Position generator on front and rear mounting

and lock washers.

brackets and install mounting hardware through rear bracket

(3) Attach commutator end head to body with four

and slotted arm of front bracket but do not tighten.

screws and lock washers.

(2) Install fan belt onto pulley of generator. Move

(4) Insert brushes into brusholders. Attach cover

generator in slotted bracket to apply proper tension to fan belt.

band to body.

Hold generator in this position and tighten mounting hardware.

Proper tension is attained when belt will not deflect more than

Installation.

1/2 inch.

(3) Attach electrical leads from voltage regulator.

(1) Position starting motor on engine and secure with

three screws and lock washers through flange of motor.

4-18. STARTING MOTOR REPAIR AND REPLACEMENT.

Repair or replace engine starting motor as follows:

4-7