Bearing Inspection - Doosan DX140R Shop Manual

Be extremely careful when installing sealing members, to
avoid cutting or scratching. Curling under of any seal lip will
seriously impair its efficiency. Apply a thin coat of Loctite
#120 to outer diameter, of metal casing, on oil seals to
assure an oil tight fit into retainer. Use extreme care not to
get Loctite on lips of oil seals. If this happens, that portion
of the seal will become brittle and allow leakage.
When replacing lip type seals, make sure spring loaded
side is towards oil to be sealed.
5. If available, use magna-flux or similar process for checking
for cracks that are not visible to the eye. Examine teeth on
all gears carefully for wear, pitting, chipping, nicks, cracks
or scores. Replace all gears showing cracks or spots
where case hardening has worn through. Small nicks may
be removed with suitable hone. Inspect shafts and quills to
make certain they have not been sprung, bent, or splines
twisted, and that shafts are true.
NOTE: Spline wear is not considered detrimental
except where it affects tightness of splined
parts.
Inspect thrust washers for distortion, scores, burs, and
wear. Replace thrust washer if defective or worn.
6. Inspect bores and bearing surfaces of cast parts and
machined surfaces for scratches, wear, grooves and dirt.
Remove any scratches and burrs with crocus cloth.
Remove foreign material. Replace any parts that are
deeply grooved or scratched which would affect their
operation.

Bearing inspection

The conditions of the bearing are vital to the smooth and
efficient operation of the machinery. When any component
containing bearings is disassembled, always carefully examine
the condition of the bearings and all of its components for wear
and damage.
Once the bearing is removed, clean all parts thoroughly using a
suitable cleaning solution. If the bearing is excessively dirty soak
the bearing assembly in a light solution and move the bearing
around until all lubricants and or foreign materials are dissolved
and the parts are thoroughly clean.
When drying bearings, moisture free compressed air can be
used. Be careful not to direct the air in a direction which will
force the bearing to dry spin while not being properly lubricated.
After the bearings have been cleaned and dried, carefully
inspect all bearing rollers, cages and cups for wear, chipping or
nicks. If the bearing cannot be removed and is to be inspected in
place, check foe roughness of rotation, scoring, pitting, cracked
or chipped races. If any of these defects are found replace the
whole bearing assembly. NEVER replace the bearing alone
without replacing the mating cup or the cone at the same time.
General Maintenance Procedures SP000016
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