Pontiac tempest 1968 Service Manual page 357

6E-8
1968 P O N T I A C SERVICE MANUAL
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-11).
(CHECK FOR GROUNDS)
OHMMETER
c o l
ST
OHMMETER
(CHECK FOR OPENS)
F i g . 6E-11 Checking Rotor
2. To check for opens, connect test lamp or
ohmmeter to each slip ring. If lamp fails to light
or if the ohmmeter reading is high (infinite), winding
is open (Fig. 6E-11).
3. The winding is checked for short circuits by
connecting a battery and ammeter in series with two
slip rings. The field current at 12 volts and 80°F
should be between 2.2 - 2.6 amperes on standard
regulator cars and 4.0 - 4.5 on cars equipped with
62 amp alternators. Any ammeter reading above
these values indicates shorted windings.
4. Rotor assemblies which fail above test should
be replaced.
The rotor may be cleaned and inspected as follows:
a.
they
spirits
If magnetic poles of rotor need cleaning,
may be cleaned by brushing with oleum
CAUTION: Do not clean with degreasing solvent.
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 sand­
paper. Spin rotor in lathe or otherwise spin rotor,
and hold polishing cloth against slip rings until
they are clean.
CA UTION: 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 read­
ing. Remove only enough material to make rings
smooth and round. Finish with 400 grain or finer
polishing cloth and blow away all dust.
DRIVE END FRAME BEARING
1. Remove three screws from retainer plate and
remove retainer plate inner collar and gasket.
2. Press out bearing and oil slinger.
3. The bearings in generator are permanently
lubricated and require no lubrication during life of
bearing. If a dry bearing is encountered, do not
attempt to lubricate, as an improper lubricant or
excessive amount of lubricant may burn bearing, or
be thrown off and contaminate inside of generator.
Replace dry, worn or rough bearings with new bear­
ings, which are prepacked with proper amount and
type of lubricant.
4. To install, press in bearing and grease slinger
with tube or collar that just fits over outer race.
5. Install retainer plate gasket and inner collar
with three screws. It is recommended that new re­
tainer plate be installed if felt seal is hardened or
excessively worn.
STATOR
If stator is to be checked and/or replaced:
1. Remove 3 stator lead attaching nuts and wash­
ers (Figs. 6E-12 or 6E-13).
2. Separate stator from end frame. The fit be­
tween stator frame and end frame is not tight, and
two can be separated easily.
3. The stator windings may be checked with 110-
volt test lamp or ohmmeter as follows:
a. To check for grounded windings, connect
lamp or ohmmeter from any stator lead to frame.
If lamp lights or ohmmeter reading is low the
stator is grounded (see Fig. 6E-14).
b. To test for opens, successively connect 110-