Piper Navajo PA-31 Service Manual page 244

PIPER NAVAJO SERVICE MANUAL
5-72. DISASSEMBLY OF FLAP ACTUATOR MOTOR. (Refer to Figure 5-19.)
a. Remove nuts (2), lockwashers (3) and screws (4) from motor.
b. Remove rear end bell (1) from sleeve and magnet assembly (18).
c. Remove front end bell (5) from sleeve and magnet assembly.
d. Remove armature assembly (17) from sleeve and magnet assembly.
CAUTION
Strong magnet pull will be encountered when removing the
armature from the sleeve and magnet assembly.
e.
Remove spring washer (16) and ball bearing (15) from armature shaft.
f. Remove brushes (6) and brush springs (7) from brush holders.
g.
Remove four screws (9) and insulator assembly (8) from front end bell (5).
h. Remove nuts (11), lockwashers (12), contact studs (10) and nylon shoulder washers (13) from
front end bell.
5-73. SERVICE OF FLAP ACTUATOR MOTOR.
a. Wash all disassembled parts except brushes, bearings and armature with a suitable dry cleaning
solvent.
b.
Examine all parts for cracks, burrs and corrosion.
c.
Visually inspect the armature for the following:
1. Commutator for pitting, scoring or burning.
2.
Loose windings.
3.
Damaged or worn splines.
4. Worn shaft caused by bearing seizure.
d. Except for repairs to commutator, all parts found to be defective or worn must be replaced with
new parts. Do not attempt to repair defective parts. Ball bearings must be replaced at overhaul.
e.
Commutator may be turned down to a minimum diameter of 1.093 inch. Polish with fine grade
sandpaper.
d.
Measure length of brushes. If less than .437 inch they must be replaced.
g. Electrically test the armature as follows:
1. Bar to bar continuity. Resistance readings should be the same when measuring two adjacent
bars as measurement is stepped around commutator.
2.
Insulation resistance between commutator and shaft should be 10 megohm minimum at
85v.
Reissued: 10/12/79
SURFACE CONTROLS
Effectivity
CALCO
1K4