dry, dip it in clean, light oil to prevent corrosion, and
of the assembly. Slight modifications on the part of
continued contact of unlubricated bearing surfaces. Drain
personnel should be made as necessary to facilitate the
off the excess oil and place bearing in a clean container
work on any particular item.
or wrap until ready for inspection. The following defects
cannot be rectified and require replacements of the
Bearings, when required, must be
maintained in proper condition to prevent wear and
Rust spots on balls or races.
misalinement of moving parts on which they are installed.
Worn or badly scored surfaces.
b. Removal. Bearings are usually
a press fit
shaft but occasionally they may be pressed in the bore of
a bearing housing. When removing or installing a bearing
Defective shield, seal, or separator.
on a shaft, always apply the pressure on the inner race.
Badly discolored balls or races caused by
When removing or installing in a bore, always apply
pressure on the outer race. Do not transmit lateral
pressures through the bearing from one race to another.
Pressing. Press bearings from shafts
Bearing catching at one or more points
of housings whenever possible. Use firm,
caused by damage not by dirt.
steady pressure and do not allow the
Excessive looseness or end play.
bearing, shaft, or housing to drop on the
Clean shaft or housing before
floor or ground.
replacing a bearing. Pack the bearing with the proper
Pulling. Bearings may be pulled if a press
lubricant. Install by pressing, the preferred method, or
is not available.
The puller must be
arranged to apply pressure on the retained
Pressing. Apply pressure on the held race
only. When pressing on a shaft, support
Driving. Bearings can be removed by
the bearing so that the inner race takes the
driving, using a soft drift carefully placed
pressure. When installing in a housing,
against the held race. Split pipe or tubing
apply pressure against outer race. Use a
with welded lugs can be used to control
suitable mandrel and blocks so that
application of the driving pressure.
pressure is applied evenly around the race.
Alternate the blows on opposite sides of the
Driving. When a press is not available,
race to prevent wedging the bearing. Be
drive the bearing to its seat by using a soft
careful not to damage splines on the shaft
drift against the held race. Alternate blows
or in the housing.
around the bearing to prevent cocking and
c. Inspection and Repair.
Wipe off as much
possible wedging. Start bearing straight
lubricant as possible. Agitate bearing in clean solvent,
and be careful not to damage shaft or
being careful not to spin the races. Remove bearing from
solvent and flat-slap bearing against a wood block to
Installation aids. Coating a shaft with white
remove solvent and shake loose any coagulated lubricant.
lead before attempting to install parts will
Place bearing back in clean solvent and continue
prevent binding and simplify installation. If
agitating until all traces of old lubricant is removed.
necessary, heat a very tight fitting bearing
When bearing is clean, remove it from the solvent, shake
to 250F. in a clean oil bath. Always, dry
out as much as possible, and blow dry with compressed
and repack bearings that have been
air directed across the races. As soon as the bearing is