TM 5-3810-289-10
immerse in a solvent. Tank should have a screened
doubt, check against endplay feel of identical new
false bottom to prevent settings from being stirred up into
bearing. Races and balls are dull gray when lapped by
the bearings. Agitate basket frequently until grease, oil
dirt.
or sludge is thoroughly loosened and can be flushed out.
(9) Any looseness or endplay which can be
(2) Bearings that contain especially heavy
detected by hand feel is a cause for rejection only in the
carbon deposits or hardened grease should be put in a
case of double row angular contact bearings.
basket by themselves and soaked in a separate
e. Bearing Mounting.
container or solvent.
(1) An arbor press is the most satisfactory tool
(3) Using a spray gun with air filter and a
for mounting bearings. Used properly, no Slows are
clean solvent, flush each bearing until all dirt or residue is
struck and there is no danger of loosening shields or
removed. Turn one of the races slowly while flushing to
seals from this cause.
help dislodge dirt from around balls and separator
(2) Place the bearing on two flat blocks of
sockets.
equal size so that they contact the inner ring of the.
(4) With dry, filtered air, blow solvent out of
bearing. Then press shaft straight until the bearing is
bearings, being careful not to spin by force of air Since
seated solidly against the shaft shoulder. Be sure that
dry bearings rust quickly, lubricate them at once.
the blocks do not scrape or damage the threads if the
(5) Dip bearings in clean light spindle oil.
shaft is threaded for a bearing locknut.
Rotate them a few times and after draining the excess oil
(3) Use of blocks that contact both rings is
place them in a covered container for inspection.
also good practice, provided the blocks are flat and the
d. Bearing Inspection. Discard bearings which
faces parallel.
show any of the following:
(4) Where the distance from shaft end to
(1) Rusted balls or raceways. Usually caused
bearing seat is short, a piece of pipe or tubing may be
by water passing worn or defective seals or by
used. The pipe must be clean inside and out and the
condensation inside housing.
ends squared.
(2) Fractured ring. Forcing a cocked bearing
(5) In cases where a press is not available a
on or off a shaft will do this, as will too heavy a press fit.
piece of tubing may be used with a hammer. A plug in
(3) Worn, galled or abraded surfaces. Can be
the tubing and a shield outside help to prevent jarring dirt
caused by too loose a fit, or bearing locked by dirt and
into bearing. The hammer should be applied alternately
turning on shaft or in housing.
at opposite points to avoid cocking and particular care
(4) Broken or bent shields, seals or separator
should be taken when' the bearing is started.
Usually caused by improper uses of tools during
f. Gear Inspection and Repair.
mounting or removal.
(1) Clean gear with an approved cleaning
(5) Badly discolored balls and races. Usually
solvent being particularly careful to clean out between
due to inadequate supply of lubricant.
Moderate
gear teeth, and dry thoroughly. Inspect gear for cracks
discoloration of balls and ball track is not a cause of
or breaks. Inspect key ways in gear hub. Be sure they
discard.
are clean and open and in good condition. Check gear
(6)
General feeling of roughness which
for warpage and if it is out of true more than the
remains unchanged by thorough cleaning, indicating
tolerance given in table 2-2 replace the gear. Inspect
damage to raceways or balls, such as indenting by dirt or
teeth for wear and if worn in excess of the tolerance
pitting by corrosion.
given, replace the gear. Check teeth for any broken or
(7) Catchy or rough feeling at one or more
nubbed teeth and also for other irregularities.
points which repeated flushing will not remove and which
(2) Repair cracks or other defects in the gear
may be a spalled or fatigued spot. Thorough flushing is
by welding and grinding. If a considerable amount of
necessary to be sure it is not caused by dirt.
welding is done on one side of the gear, check before
(8)
Excessive looseness or end play,
reinstalling.
indicating lapping by dirt of abrasive in lubricant. If in
2-4
