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1-12
BEARING SERVICE
LUBRICARE
AND
BEARING SERVICE
(
20)
properly applied pressure during removal or
installation.
Bearings should be pressed on or off and not
driven, as the shock produced by
driving
may
cause
cracking,
chipping, denting or brinelling
of the hardened surfaces. Always apply the
pressure against the particular race which is a
tight fit on or in the part to which bearing is
assembled,
so that the pressure
is
not trans-
mitted through the balls or roll
ers.
N
ever press
or
drive
on the loose
race.
Never attempt to mount a bearing on or in
a part where the bearing seat is distorted,
burred, or scored. The bearing seat must first
be trued and smoothed up and given a light
coat of oil.
Never apply full force against a bearing until
assured that the bearing is started straight.
Forcing a cocked bearing distorts the tight
fitted race and may cause it to crack; further-
more, the extremely hard race is likely to
distort,
burr,
or score the bearing seat of adja-
cent part. The same rule applies when removing
the bearing.
1-12 CARE OF BEARING BEFORE
CLEANING
Do not drop bearing on floor or on other
parts on
bench.
Never spin ball or roller
bearings,
especially
not with an air
hose.
Considerable damage can
be done if a bearing
is
spun at high speed ;
furthermore, this is a useless procedure since
the condition of a bearing cannot be determined
by spinning, even at low speed.
Very few bearings
removed
in service work
are entirely free from
dirt
or other foreign
substances. In a majority of cases there is
enough dirt present to affect the
"feel"
of the
bearings and give the impression that they are
rough or noisy. This is particularly noticeable
in the double row ball bearings due to their
initial
preload.
The condition and serviceability of ball and
roller bearings that hav e
been
in service cannot
be judged until
they are thoroughly
cleaned,
lubricated, and inspected
as
described below.
Do not lay bearings
down on a bench where
dirt and metal particles are liable to get into
them. Keep bearings separated from other
parts to avoid damage and contamination with
foreign substances.
Immediately after removal of bearings wrap
them in dry, clean paper until they can be
washed, lub ri cated, and in
sp ect ed as
to
fitness
for
fu
rther
service.
Be sure
wrapped bearings
are well lubricat ed to
prevent
rusting.
1-13 CLEANING BEARINGS
Bearings havi ng seals or shields on
both
sides shou ld
never
be
washed
since
t
he lub
ri-
cant ma
y
be diluted
or washed out. Wip
e
exterior
dirt
from
such
bearings with
a clean
cloth.
Bearings
(not
sealed on both
sides)
should
be
thoroughly washed in clean gasoline or
kero-
sene which
has not been used for other
part s.
It
may
be
necessar y to
soak
very dirty
bearings
in the clean
ing fluid
f
or some time, to
soften
hardened
dirt
an
d lubricant so it can
be
washed out.
String a
bear ing on a wire and
slosh
it
up
and down in
cleaning fluid to wash
out old
lubricant and dirt. A bearing
having
a shield
on one side only should
be strung with
shi elded
side up to permit dirt
to dr op out r
eadily.
After
sloshing on the
wire, the
bearing shou ld be
rotated and
sloshed in
cleaning fluid
by
hand t
o
complete the
r
emoval
of all foreign
substances.
When soaking or washing
bearings,
us
e
care
not to contact
bottom of
container and
thereby
pick up
any
dirt
t
hat
may have
settled.
Do
n
ot
string
several bea r in gs
on
wire as the lower
bearing may becom
e
contaminated wit h
dirt
or
metal particles washed
from upper
bearings.
Owing to
t
heir
great er width and
construc-
tion, double row beari ngs
re
quire
a
very
thorough
washing
t
o remove all dirt or
oth er
foreign substan ces.
After washing,
blow out bea
rings with clean,
dry air. Let
air run a wh
ile
before turning
it
into
bearings,
to eliminate
line dirt
and
mois-
ture. Direct
the ai
r
st re am squarely into the
open side or face of
bearing while holding
t
he
inner race and slowly
rotating
the outer
r
ace
by hand. Continue until all
loose dirt ·is
r
e-
moved. The air stream
must not
be directed
so
as to spin the
bearing
while
cleaning,
because
a
very high speed can be
attained
and
cons id-
erable
scratching and
scoring
will be
done
be-
for e the dirt is blown
out.
After t
he
bea r ing
is
t
hor oughly
cleaned,
oil
bearing with clean ne
w
engine
oil,
rotating
the bearing by hand to
distribute the lubri cant
to all surfaces.
If
bearing
is not to
be inspected
immediatel y,
wrap it in
clean,
oiled
pap er t
o
protect it from
dirt and
du
st.
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