GMC 4000 Series Service Manual page 410

STARTER REPLACEMENT
REMOVAL
1. Remove ground strap from battery negative
(-) post or tape end of battery cable when discon­
nected from starter solenoid to prevent discharge
of battery by direct short.
2. Disconnect wires from solenoid terminals.
3. Remove bolts, nuts, and lock washers at­
taching starter to flywheel housing and pull starter
forward to remove. Remove spacer (if used).
INSTALLATION
1. Position starter and spacer (if used), at
flywheel housing and secure with bolts, nuts, and
washers. On gasoline engine models, tighten mount­
ing bolts to 25-35 foot-pounds torque. On D iesel
engine models, tighten mounting bolts to 70-80 foot­
pounds torque.
2. Connect all wires to starter solenoid term ­
inals, referring to "Wiring Diagrams" in applic­
able "Wiring Diagrams" booklet to make sure of
proper connections. Tighten terminal nuts firmly.
PINION CLEARANCE CHECK
The drive pinion clearance should be checked
whenever starter has been overhauled. There is
no means of adjusting the pinion clearance on the
light duty starting motors. If clearance is not with­
in specified lim its, it may indicate excessive wear
of the solenoid linkage or shift lever yoke lugs.
Clearance between the end of the pinion and pinion
stop (retainer), with pinion in cranking position,
should be 0.010"-0.140".
1. Connect a voltage source of approximately
6 volts between the solenoid switch terminal (S)
and ground.
IMPORTANT: DO NOT connect voltage source
to ignition coil (R) terminal of solenoid. Do not
use a 12-volt battery in place of the 6-volt battery
G M C S E R V I C E M A N U A L
PRESS O N CLUTCH
A S S H O W N TO
TAKE UP M O V E M E N T
specified in Step 1 previously, as this will cause
the starter to operate. As a further precaution,
connect a heavy jumper lead from solenoid motor
terminal to ground (fig. 6) to prevent motoring.
ed forward), push pinion back toward commutator
to take up possible slack. Check clearance with a
feeler gauge as shown in figure 7. If clearance is
not within 0.010" to 0.140", disassemble and re­
place worn parts in solenoid and shift lever linkage.
starting motor has been overhauled. If necessary
test equipment is available, accomplish following
steps to perform free speed check:
an ammeter to "battery" terminal of solenoid on
starting motor.
motor to negative (-) post on battery.
terminal to ground.
indicator to starting motor.
STARTING SYSTEM
Figure 7— M easuring Pinion Clearance
2. After energizing the solenoid (clutch shift­
STARTER FREE SPEED CHECK
(Refer to Figure 8)
The free speed check is recommended after a
1. Connect a 12-volt battery in series with
2. Connect a lead from frame of starting
3. Connect a voltmeter from solenoid battery
4. Install a tachometer or any suitable rpm
Sec. 6Y
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