(2) Inspect needle bearings for wear, scoring,
(15) Install adjusting screw 171) by turning
adjusting screw the same number of turns required
(3) Inspect idler shaft for wear, scoring, or
(16) Install copper gasket (6) and cap nut (5)
(4) Drive and idler shafts should be .4387 inch
on adjusting screw.
f. Adjustment. The power steering pump is
diameter, minimum. Input end of drive shaft should be
adjusted, after installation, according to paragraph 2-12.
.5000 inch diameter, minimum.
3-40. Power Steering Pump Motor
(5) Inspect drive shaft for wear, scoring, or
a. General Troubleshooting.
(1) For excessive noise: Inspect motor for
(6) Check oil seal in gear housing for damage
loose parts (thrubolts and hold-down screws), improper
or leakage of oil.
alignment of cover bands, unbalanced armature, and
(7) Inspect gears and gear housing for wear,
galling or scoring.
(2) For hot motor: Heat measured with a
(8) Inspect pump coupling for wear or dam-
thermometer should not exceed maximum temperature
rise as indicated on motor nameplate.
(9) Replace all parts that are worn or
(3) For excessive load: Excessive load may
prevent motor from starting or accelerating to full speed.
e. Reassembly. (fig. 3-71.)
Check for excessive load by measuring current input to
Insure that each part
is coated with hydraulic oil before
(4) Armature and field coil overheating: Test
armature and field coils according to subparagraph f
(1) Carefully install needle bearings (18) and
oil seal (11) in stator and gear housing.
b. Removal. Remove the power steering pump
(2) Carefully slide drive shaft (10) through oil
motor according to paragraph 2-13.
seal in gear housing.
c. Inspection. Minimum diameter for un-
(3) Install one snap ring (15) and key (17) on
dercutting is 2 1/8 inches.
(1) Loosen screw and remove cover band to
(4) Position gear (13) on shaft and secure in
gain access to commutator and brushes.
position using a second snap ring (15).
(2) Clean and blow out accumulated dirt and
(5) Preassemble idler shaft assembly before
dust. Dirt in vent passages and air gap may cause
installing in gear housing:
(a) Position pin (14) in idler shaft (12)
Caution: Do not use emery
and install one snap ring (16).
cloth or paper on the commutator.
(b) Slide idler gear (13) into position on
idler shaft and secure using a second snap ring (16).
roughness, or high mica. If rough or blackened, clean by
(6) Position idler shaft assembly into gear
holding a piece of 00 sandpaper against the commutator
with a block of wood. Carbon film on commutator is
(7) Mesh idler shaft gear with drive shaft
normal and should not be removed.
Caution: Do not use lubricant
(8) Measure running clearance between gears
or solvent on commutator.
and gear housing.
(4) Mica undercut depth is 1/64 inch
(9) Insure that running clearance is between
minimum, 3/64 inch maximum. Sides of commutator
0.0003 and 0.0008 of an inch.
bars should be free of mica. Undercut, if necessary, with
Note. Shims are manufactured
a piece of hacksaw blade.
in five thicknesses: 0.00025, 0.0005,
(5) Inspect armature and field coils for
0.0003, 0.002, and 0.001 inch.
charred or burned varnish or insulation. A burned
(10) Select proper thickness of shims to obtain
condition indicates overheating caused by a
the proper gear to housing clearance.
malfunctioning in the armature or field coils. Excessive
(11) Position shim(sl on gear housing mating
overheating can destroy armature coils and burn
surface and assemble housings.
commutator bars. If this condition is found, the motor
(12) Secure stator and gear housing using
should be replaced.
d. Brush Inspection and Replacement.
(13) Torque screws to 130 inch-pounds.
(1) Depress brush spring .13, fig. 3-72) and
(14) Position ball and spring assembly (8) in
remove from brush holder assembly (4).
relief valve port.
(2) Remove screw (11 and take out brush (2).
(3) With brushes out, inspect commutator