TM 5-3895-359-14&P
the drive unit and replace if rollers or cups
is used, water is trapped in the cored passage of the
are pitted or damaged in any way.
castings and in the close clearances between parts as
Remove parts needing replacement with a
well as on the parts. This can lead to corrosion (rust) of
suitable puller or in a press with sleeves.
critical parts of the assembly and the possibility of
circulating rust particles in the lubricant. Premature
Avoid the use of drifts and hammers.
They may easily mutilate or distort
by this practice. Assembled drive units cannot be
component parts.
properly cleaned by steam cleaning, dipping
or
B. Inspect first reduction bevel or hypoid and
slushing.
Complete drive unit disassembly is a
second reduction spur gears for wear or
necessary requisite to thorough cleaning.
damage. Gears which are pitted, galled or
ROUGH PARTS
worn or broken through case hardening
Rough parts such as differential carrier castings,
should be replaced. When necessary to
cast brackets may be cleaned in hot solution tanks with
replace the pinion or gear of a gear set,
mild alkali solutions providing these parts are not ground
the entire gear set should be replaced.
or polished. The parts should remain in the tank long
We assume no responsibility for gears of
enough to be thoroughly cleaned and heated through.
these types when replaced in any other
This will aid the evaporation of the rinse water. The
manner.
parts should be thoroughly rinsed after cleaning to
C. Inspect the differential assembly for the
remove all traces of alkali.
following:
1. Pitted, scored or worn thrust surfaces of
WARNING
differential case halves, thrust washers, spider
Exercise care to avoid skirt rashes
trunnions and differential gears. Thrust washers
and inhalation of vapors when using
must be replaced in sets.
The use of a
alkali cleaners.
combination of old and new washers will result
COMPLETE ASSEMBLIES
in premature failure.
Completely assembled axles may be steam cleaned
2. Wear or damage to the differential pinion and
on the outside only, to facilitate initial removal and
side gear teeth.
disassembly, providing all openings are closed.
Always replace differential pinions and side
Breathers, vented shift units, and all other openings
gears in sets.
should be tightly covered or closed to prevent the
D. Spur pinions for wear or damage to teeth.
possibility of water entering the assembly.
DRYING
E. Check end of pinion for indications of
Parts should be thoroughly dried immediately after
brinelling caused by worn splines.
cleaning. Use soft, clean, lintless absorbent paper
Replace the parts if the splines of the
towels or wiping rags free of abrasive material, such as
pinion and/or thru-shaft are worn,
lapping compound, metal filings or contaminated oil.
permitting movement of the pinion on the
Bearings should never be dried by spinning with
thru-shaft.
compressed air.
F. Axle shafts for indications of torsional
CORROSION PREVENTION
fractures and runout. Axle shafts should
Parts that have been cleaned, dried, inspected and
be inspected between centers to ascertain
are to be immediately reassembled should be coated
the amount of runout of the ground
with light oil to prevent corrosion. If these parts are to
surfaces. Runout at the shaft flange and
be stored for any length of time, they should be treated
splines should not exceed .005" total
with a good RUST PREVENTIVE and wrapped in
indicator reading.
special paper or other material designed to prevent
corrosion.
REPAIR
INSPECT
A. Replace all worn or damaged parts. Hex
It is impossible to overstress the importance of
nuts with rounded corners, all lock
careful and thorough inspection of drive unit parts prior
washers, oil seals and gaskets should be
to reassembly.
Thorough visual inspection for
replaced at the time of overhaul.
indications of wear or stress, and the replacement of
such parts as are necessary will eliminate costly and
Use only genuine Rockwell-Standard
avoidable drive unit failure.
parts for satisfactory service.
For
A. Inspect all bearings, cups and cones,
example, using gaskets of foreign
including those not removed from parts of
material generally leads to mechanical
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