g. Inspect, clean, and repack generator or motor bearing assemblies.
To prevent bearing
failures, observe the following precautions.
(1) When removing coupling flange or blower fan wheel assembly, use a puller that does not
apply a load on the bearings.
(2) Press coupling flange or blower fan on the shaft in such a way that the forces are not
transmitted through the bearings.
(3) Prevent bumping of auxiliary generator shaft; this can damage the bearings.
(4) Do not reuse bearings which have been removed from the shaft at any time; instead
replace them with new factory-packed bearings.
h. Tolerances on traction motor axle bearings vary slightly depending on the manufacturer of
the locomotive and whether it is to be used in road or switcher service. The manufacturer's maintenance
instructions or appropriate technical manuals should be followed when bearings are to be repaired or
renewed. Whenever a traction motor is removed from a locomotive, the bearing alinement should be
checked before the motor is reinstalled in the locomotive. If a bearing shows a sign of cutting, scrape it
down to a new surface; if too badly worn, replace with a new one. Before installing bearings, examine
the journal for roughness or cutting.
If bearings are hot, check oil level in the oil cavity, examine waste packing to make sure it
has not fallen away from journal, and check bearing clearance.
i. Traction motor axle and pinion gears are removed with a gear puller. Never heat the gear
before pulling and never use wedges between the gear and the bearing cap. To prevent damage to
antifriction bearings, remove the armature from the motor frame, place it in suitable V-shaped supports,
and then pull off pinion gear. Never strike the pinion gear or gear puller with a sledge or any heavy
object while the armature is in place in the motor frame.
The end of the armature shaft on which the pinion gear is mounted and the bore of the pinion
gear are tapered. When reinstalling the traction motor pinion gear, first clean the tapered portion of the
armature shaft and the bore of the pinion thoroughly and remove any surface scoring. Coat the tapered
surface of the armature shaft with a very light coating of bluing spotting compound.
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