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TM 10-3930-643-34
GENERAL MAINTENANCE PROCEDURES. (cont)
2-14.
Bearing Procedures.
Special care should be taken when removing,
cleaning, inspecting and installing bearings.
The following procedures are
recommended to avoid problems that could occur from
improper handling of
bearings:
a. Bearing Removal.
(1) Keep area around bearings clean.
Prevent loose dirt from entering
bearings. Study the assembly before removing bearing and handle carefully.
(2) The best tool for removing a bearing is an arbor press. Press only
on the race that is tight.
Press evenly to prevent the race from cocking and
scoring the shaft or damaging the bearing.
Keep press table and support blocks
clean and square.
Prevent the shaft from falling on the floor.
Protect the
end of the shaft with a pad of lead, copper, or hardwood.
(3) If an arbor press is not available, use a bearing puller.
Install
bearing pullers to pull or push bearings straight and square. Do not damage
threads, keyways, and shoulders.
(4) With proper care, bearings may be removed safely with
if the proper tools are not available.
A vise and drift may be
of an arbor press and press ram.
If the shaft is to be held in
its surface with a copper sheet or hardwood blocks.
A hardwood
other
methods
used in place
a vise, protect
block may be
used to permit hammer blows to be struck dead center and prevent bearing
from
cocking.
(5) If the bearing fit does not permit the use of a bearing puller or
arbor press, grind off or cut off with an acetylene torch.
Cut the outer race
and ball retainer and burn the inner race part way through to avoid
damaging
the shaft.
Crack the race the rest of the way using a hammer and chisel.
Use
caution to avoid personal injury from flying parts.
b.
Cleaning Bearings.
(1) Clean all bearings before installation. An accurate judgement about
the condition of a bearing cannot be made unless it is thoroughly free from
dirt.
Do not spin dirty bearings. Rotate them slowly while cleaning in
cleaning solvent P-D-680.
Bearings with a shield or seal on one side only
should be cleaned and inspected in the same way as other bearings.
Bearings
with shields or seals on both sides should not be cleaned in cleaning
solvent
P-D-680.
Wipe with a clean cloth to prevent dirt or other contamination.
(2) Dry bearings thoroughly with compressed air. When drying bearing,
rotate to expose all parts of the bearing.
2-26
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