
SEBU8219-01 85
Maintenance Section
Bearing - Inspect
i02230503
Bearing - Inspect
SMCS Code: 4471-040
The following m
aintenance procedure for generator
bearings should be followed at every major engine
overhaul:
1. Remove the bearing bracket. Inspect the following
items: bracket bore, bearing outer race, and
rolling eleme
nts. On standby power units, the
bearing must be inspected and the grease must
be replaced at three year intervals. The sleeve
for the beari
ng bracket should be inspected for
out of roundness, excessive wear, and a bracket
step that is less than 0.0762 mm (0.0030 inch). If
thereisnos
leeve for the bearing bracket, inspect
the bore for the bearing bracket. The bearing
should be inspected for damage to the outer race,
severe fret
ting, and smoothness of operation.
When possible, the bearing elements should be
inspected. Some double shielded ball bearings
prevent vi
sual inspection of the ball bearings.
Other double shielded ball bearings have a
retaining ring. This retaining ring can be removed
in order to
allow access for a visual inspection o f
the ball bearings.
On two-be
aring generators, the front bearing can
only be removed after the hub is removed. In order
to remove the hub, cut off the hub. Pulling the hub
will dama
ge the shaft.
Note: Bearings that are being removed for failure
analysi
s should not be cut off with a torch.
2. Spherical Roller Bearing should be cleaned and
repacke
dwith108-8611 Grease. Pack the
bearing and pack the cavity (one-third to one-half
of the volume of the cavity). The bearing should
be filled
with 88.8 mL (3 ounces) to 118.4 mL
(4 ounces) of grease. The cavity should be filled
with 118.4 mL (4 ounces) to 148.0 mL (5 ounces)
of grea
se. Refer to Table 11.
3. All ball bearings should be cleaned. The cavity
of the b
racket should be repacked with 2S-3230
Grease. Pack the bearings (one-third to one-half
of the volume of the cavity). Refer to Table 11.
To reinstall bearings, heat the bearings to 107 °C
(224.6 °F) for ten minutes. Mount the bearings
on the
shaft. To reinstall the hub, heat the hub to
400 °C (752.0 °F) for three hours. Mount the hub
to the shaft.
4. Ensure that the tube that supplies grease to the
bearing is filled with grease.
5. Remove the brac
ket drain plug and operate the
generator for one hour. This will allow the grease
to expand. The expanding grease will force the
excess grease
from the cavity. When the excess
grease is forced from the cavity, the internal
pressure will be reduced. The generator should
continue to o
perate until the grease stops purging.
6. Stop the engine. Install the bracket drain plug.
Wipe off the e
xcess grease.
7. For greasing intervals, follow the recommendations
on the lubric
ation plate (if equipped) or refer to
Maintenance Schedule, “Bearing - Lubricate”.
Whenever the bearings are greased, repeat Step
5. DO NOT MIX
GREASES.