Cadillac 60 Series 1963 Shop Manual page 291

12-10
ELECTRICAL SYSTEM
|Press On Clutch As Shown To Take Up Movement
Pinion
Retainer
Feeler Gauge
.010/.140 Pinion Clearance
Fig. 12-11 Checking Pinion Clearance
2. Energize solenoid by applying 6 volts between
solenoid " S " terminal and ground.
CAUTION: Do not use more than 6 volts or
motor will operate. As a further precaution,
connect a heavy jumper wire from the solenoid
motor terminal to ground.
3. After energizing solenoid, press on clutch,
Fig. 12-11, to take up movement.
4. Push pinion away from stop retainer as far
as possible and use feeler gage to check clearance
between starter motor pinion and pinion stop re-
tainer, Fig. 12-11. Clearance should be .010 inch
to .140 inch when pinion is in cranking position.
NOTE: Pinion clearance cannot be adjusted.
If clearance is incorrect, disassemble starter
motor and check for excessive wear of solenoid
linkage, shift lever mechanism, or improper
assembly of these parts. All defective parts
must be replaced.
14. Checking Inoperative
Starter Motor
If starter motor does not develop rated torque,
and cranks engine slowly or not at all, check bat-
tery, battery terminals and connections, ground
cable, and battery-to-starting motor cable. Cor-
roded, frayed, or broken cables should be re-
placed, and loose or dirty connections corrected.
The overrunning clutch should withstand 50 to
60 foot pounds torque without slipping. The pinion
should turn freely and smoothly in the overrunning
direction. The solenoid switch contacts should
be checked for a burned condition, and the contact
disc and terminal studs should be replaced if nec-
essary.
Inspect brushes and commutator. Brushes
should form a good contact with commutator and
have the correct spring tension. If there are
burned bars in the commutator, it may indicate
open circuited armature coils that may prevent
proper cranking. Inspect soldered connections at
commutator rise bars, and resolder these con-
nections and turn down the c o m m u t a t o r as
necessary.
Tight or dirty bearings will reduce armature
speed or prevent the armature from turning. A
worn bearing, bent shaft, or loose pole shoe will
allow armature to drag, causing slow speed or
failure of the armature to rotate. Check for these
conditions. If brushes, bearings, commutator,
and external circuit are all right, and starter
motor still does not operate correctly, remove
starter motor for Bench Check as to NO-LOAD
and resistance tests.
15. Starter Motor Test
a. No Load Test
1. Connect starter motor and solenoid in series
with the battery through ammeter leads of Battery
Tester, or suitable ammeter capable of indicating
400 amperes. Connect positive voltmeter lead of
tester to battery terminal of solenoid and connect
negative lead to starter motor housing.
2. Connect jumper wire from battery terminal
of solenoid to solenoid winding terminal, thus
energizing starter motor.
3. Vary carbon pile resistance until voltage
across motor and solenoid is 10.6 volts. Current
draw of motor and solenoid should be 65-100 am-
peres.
b. Lock Load Test (Resistance Test)
Check capacity of motor by using a 500 ampere
meter and a carbon pile rheostat to control volt-
age. Apply 3-1/2 volts across motor with arma-
ture locked. Current should be 300- 360 amperes.
16. Interpretation of No-Load and
Resistance Tests
1. Low free speed and high current draw with
low torque:
a. Tight, dirty or worn bearings, bent shaft or
loose pole shoes.
b. Grounded armature or field. Check further by
isolating various parts of motor and checking with
a test lamp to determine location of ground.
NOTE: End of shunt field coil must be dis-
connected from ground before checking for
grounded armature or field.