(b) Be sure both hands are dean, place a new bushing on the palm of the hand, and fill it with SAE 20
lubricating oil. Place the thumb of the free hand over the open end of the bushing, and push hard to
pressurize the oil in the bushing. The bushing is properly lubricated when the oil seeps through the
entire outside diameter of the bushing.
Do not drill, ream, or machine bronze bushings. Machining will seal or plug the bushing
pores, and prevent proper lubrication.
If the new lubricated bushing is not going to be installed immediately, store it in a dean
Install the new, lubricated drive housing and housing lever bushings (24 and 32) or sleeve bearing
(45) using the correct size bushing driver. Be sure the bushing is started square and driven straight
into the housings (21, 28, or 43) until level with, or slightly below the thrust surface. The bushings
are sized to be a correct fit on the armature shaft when installed. Do not ream, drill, or otherwise
machine the bushing.
(d) Check the fit of the bushings or bearing on the armature (63). The correct clearance should be
0.0015 to 0.003 inch (0.038 to 0.08 mm). If the bushing fits too tightly, it was incorrectly installed;
remove the damaged bushing and install a new one. If the fit is too loose, check the armature shaft
Replace the armature (63) for the following defects: thrown solder (from overheating), loose windings,
loose commutator bars, bushing surface worn or scored over 0.003 inch (0.08 mm) deep, damaged or
uneven wear of the splines, or shaft runout over 0.005 inch (0.13 mm) TIR.
Replace the armature (63) if electrical opens, shorts, or grounds are found.
Lathe or milling operations create metal particles which may enter the eyes. Wearing of
goggles Is required to avoid Injury to personnel.
If the commutator runout is over 0.005 inch (0.13 mm), or if it is scored, uneven, or burned, resurface the
commutator using armature and undercutting lathe MIL-L-14576.
After machining, undercut the insulation between the commutator bars to a depth and width of 0.031 inch
Do not use emery cloth or paper for the following operation. Emery dust could cause
electrical shorts In the starter motor.
After machining and undercutting, remove any burrs from the commutator using sand paper P-P-105; do
not use emery cloth. After deburring, remove any sanding or copper dust from the slots between the
Avoid breathing fumes generated by soldering. Remove rings and watches. Eye protection Is
required to avoid Injury to personnel.
Varnish Is flammable and moderately toxic to the sin, eyes, and respiratory tract Skin, eye,
and respiratory protection Is required to avoid Injury to personnel.