GMC 1976 ZEO 6083 Maintenance Manual page 407

removed by detaching the retainer plate screws, and
then pressing the bearing from the end frame. If the
bearing is in satisfactory condition, it may be reused,
and it should be filled one-quarter full with Delco-
Remy Lubricant No . 1948791 or before reassembly .
CAUTION: Do not
overfill, as they may
cause the bearing to overheat.
To install a new bearing, press in with a tube or
collar that just fits over the outer race, with the
bearing and slinger assembled into the end frame. It
is recommended that a new retainer plate be installed
if the felt seal in the retainer plate is hardened or
excessively worn. Fill the cavity between the retainer
plate and bearing with 1948791 lubricant .
The bearing in the slip ring end frame should be
replaced if its grease supply is exhausted . No attempt
should be made to re-lubricate and reuse the bearing.
To remove the bearing from the slip ring end frame,
press out with a tube or collar that just fits inside the
end frame housing. Press from the outside of the
housing towards the inside .
To install a new bearing, place a flat plate over
the bearing and press in from the outside towards the
inside of the frame until the bearing is flush with the
outside of the end frame. Support the inside of the
frame with a hollow cylinder to prevent breakage of
the end frame. Use extreme care to avoid misalign-
ment or otherwise placing undue stress on the bear-
ing.
If the seal is separate from the bearing, it is
recommended that a new seal be installed whenever
the bearing is replaced . Press the seal in with the lip
of the seal toward the rotor when assembled, that is,
away from the bearing. Ligh"tly coat the seal lip with
oil to facilitate assembly of the shaft into the bearing.
GENERATOR BENCH OUTPUT TEST
To check the generator in a test stand, proceed as
follows :
1 . Make connections as shown in Figure 31, ex-
cept leave the carbon pile disconnected . IMPOR-
TANT-Ground polarity of battery and generator
must be the same . Use a fully charged battery, and
a 10 ohm resistor rated at six watts or more between
the generator No . 1 terminal and the battery.
2 . Slowly increase the generator speed and ob-
serve the voltage.
3. If the voltage is uncontrolled with speed and
increases above 15 .5 volts on a 12-volt system, check
ENGINE ELECTRICAL 6Y- 27
Figure 31-Connections for Testing Generator Output
for a grounded brush lead clip as covered under
heading of "OVERCHARGED BATTERY" Step
3 . If not grounded, test regulator with an approved
regulator tester, and check field winding. NOTE :
The battery must be fully charged when making this
check.
4. If voltage is below 15 .5 bolts on a 12-volt sys-
tem, connect the carbon pile as shown .
5. Operate the generator at moderate speed as
required and adjust the carbon pile as required to
obtain maximum current output .
6. If output is within 10 amperes of rated output
as stamped on generator frame, generator is good .
7. If output is not within 10 amperes of rated
output, keep battery loaded with carbon pile, and
ground generator field (figure 25).
8 . Operate generator at moderate speed and ad-
just carbon pile as required to obtain maximum out-
put.