Chevrolet 10 Series 1970 Service Manual page 427

CONTACT
FINGER
BRUSH
GROUNDED BRUSH HOLDER
plunger m echanism , protectin g them from d irt, splash,
and icing. The flange mounted solenoid switch operates
the overrunning clutch d riv e by means o f a linkage to the
shift le v e r .
V ariation s o f the enclosed shift le v e r type starting
m otor are used in the C h evrolet Truck P ro g ra m s . G as­
oline pow ered engines use
LUBRICATION
The gasoline engine type starting m otors have graphite
and o il im pregnated b ron ze bearin gs and th erefore r e ­
q u ire no p erio d ic lu brication between m ajor overhauls.
The V -6 D iesel engine type m otors have pipe plug o ile r s
and should have 8-10 drops o f light engine o il every
5000 m ile s o r e v e ry 300 hours of operation.
RESISTANCE CHECKS
Although the starting m otor cannot be checked against
specification s on the car, a check can be made fo r ex­
ces s iv e resistan ce in the starting circu it. P la ce a v o lt­
m eter a c ro s s points in the cranking circu it as outlined
below and o b serve the reading with the starting switch
closed and the m otor cranking (distributor p rim a ry lead
grounded to preven t engine firin g ).
1. From battery p ositive
term in al.
2. F ro m battery negative
housing.
GROMMET
BUSHING
.....■ » « « ...» ..J
INSULATED BRUSH HOLDER
BRUSH SPRING
F ig . Is —S ta rtin g M o to r Cross S e c tio n — L ig h t D uty
the conventional starting
MAINTENANCE AND ADJUSTMENTS
post to solenoid battery
post to starting m otor
SOLENOID
PLUNGER
\ FIELD COIL
ARMATURE
m otor o f eith er the flange o r pad mounted (fig s . 2s and
3s) type housing.
flange mounted starting m otor but a much h ea vier duty
design (fig. 3s). Specific mention is made w here d iffe r ­
ences in s e rv ic e procedu res between the two types of
m otors occur.
3. From solenoid battery term inal to solenoid m otor
term inal.
If voltage drop is any of above, check exceeds 0.2 volts,
ex c e s s iv e resistan ce is indicated in that portion o f s ta rt­
ing circu it and the cause o f the e x c ess ive resistan ce
could be located and co rrected in o rd er to obtain m a xi­
mum efficien cy in the circu it.
CAUTION:
Do not operate the starting m otor
continuously fo r m ore than 30 seconds to avoid
overheating.
When the solenoid fa ils to pull in, the trouble may be
due to e x cessive voltage drop in the solenoid control
circu it. T o check fo r this condition, close the starting
switch and m easure the voltage drop between the B A T ­
T E R Y term inal o f
term in a l o f the solenoid.
1. If this voltage drop exceeds 3.5 volts, excessive r e ­
sistance in the solenoid control circu it is indicated
and should be co rre cted .
ENGINE-ELECTRICAL 6Y-35
RETURN SPRING
SHIFT
LEVER
SPIRAL
SPLINES
BUSHING
PINION
STOP
OVERRUNNING
ASSIST CLUTCH
SPRING
D iesel pow ered truck engines use a
the solenoid and the SW ITCH
CHEVROLET TRUCK SERVICE MANUAL
(S)