Pontiac FIREBIRD 1972 Service Manual page 784

6E-22 1972 PONTIAC SERVICE MANUAL
3. Loosen adjusting bolts.
4. Remove generator drive belt.
5. Remove thru bolt which retains generator.
6. Remove generator from car.
DISASSEMBLE GENERATOR (SI A N D 1 0 DN)
If rotor, drive end frame bearings or pulley and fan
need replacement, remove and replace shaft nut using
hex type wrench.
Scribe a mark between two halves of generator to
help locate parts in same position during assembly.
Remove four through bolts.
Separate drive end frame and rotor assembly from
stator assembly by prying apart with screwdriver at
stator slot. The fit between the two is not tight and
the two can be separated easily.
NOTE: The separation is to be made between
stator assembly and drive end frame.
CAUTION: As rotor and drive end frame as-
sembly is separated from slip ring frame assem-
bly, the brushes will fall down onto shaft and
come in contact with lubricant. Brushes which
come in contact with shaft should be cleaned
immediately to avoid contamination by oil, or
they will have to
be
replaced.
INSPECTION A N D REPAIR (SI A N D 1 0 DN)
ROTOR (SI A N D 1 0 DN)
The rotor may be checked electrically for grounded, open
or short-circuited field coils as follows:
1. To check for grounds, connect a 110-volt test lamp
or ohmmeter from either slip ring to rotor shaft, or
to rotor poles. If lamp lights or ohmmeter reading is
low, the field winding is grounded (Fig. 6E-30).
2. To check for opens, connect test lamp or ohmmeter
to each slip ring. If lamp fails to light or if the ohmm-
eter reading is high (infinite), winding is open (Fig.
6E-30).
3. The winding is checked for short circuits by connect-
ing a battery and ammeter in series with two slip
rings. The field current at 12 volts and 80°F should
be between 4.0
-
4.5 amperes. Any ammeter reading
above these values indicates shorted windings.
JUNCTION
DELCOTRON
GENERATOR
REGULATOR
Fig.
6E-30 Checking Rotor
4. Rotor assemblies which fail above test should be re-
placed.
The rotor may be cleaned and inspected as follows:
a. If magnetic poles or rotor need cleaning, they
may be cleaned by brushing with oleum spirits.
CAUTION: Do not clean with degreasing sol-
vent.
b. Inspect slip rings for dirt and roughness. These
may be cleaned with solvent, if necessary. They
may also be cleaned and finished with 400 grain
or finer polishing cloth. Do not use sandpaper.
Spin rotor in lathe or otherwise spin rotor, and
hold polishing cloth against rings until they are
clean.
CAUTION: The rotor must be rotated in order
that slip rings will be cleaned evenly. Cleaning
slip rings by hand, without spinning rotor, may
result in flat spots on slip rings, causing brush
noise.
Slip rings which are rough or out of round should be trued
in lathe to .002" maximum indicator reading. Remove
only enough material to make rings smooth and round.
Finish with 400 grain or finer polishing cloth and blow
away all dust.