11-38. MAINTENANCE. The starting circuit should be inspected at regular intervals, the frequency of which
should be determined by the amount of service and the conditions under which the aircraft is operated. It is
recommended that such inspection be made at each 100 hours and include the following:
a. The battery should be checked with a hydrometer to be sure it is fully charged and filled to the proper level
with approved water. A load test should be made to determine battery condition. If dirt and corrosion have
accumulated on the battery, it should be cleaned with a solution of baking soda and water. (See Paragraph 11-30.)
b. The starting circuit wiring should be inspected to be sure that all connections are clean and tight and that
the insulation is sound. A voltage loss test should be made to locate any high resistance connections that would
affect starting motor efficiency. This test is made with a low reading voltmeter while cranking the engine or at
approximately 100 amperes. The following limits should be used:
1. Voltage loss from insulated battery post to starting motor terminal 0.3 volt maximum.
2. Voltage loss from battery ground post to starter frame 0.1 volt maximum.
—NOTE—
If voltage loss is greater than the above limits, additional tests should
be made over each part of the circuit to locate the high resistance
connections.
c. No lubrication is required on the starting motor except at the time of overhaul. Then lubricate the entire
shaft under Bendix Drive, fill grooves in armature shaft at drive end and pack gear box with 1.3 to 2.0 ounces of
Lithium Soap Base Grease 1925 Molytex "0" or equivalent.
d. The starting motor should be operated for a few seconds with the ignition switch off to make sure that the
pinion engages properly and that it turns freely without binding or excessive noise. Then the engine should be
started two or three times to see that the pinion disengages properly when the engine is turned off.
I1-39. OVERHAUL. If during the above inspection any indication of starting motor difficulty is noted, the
starting motor should be removed from the engine for cleaning and repair.
11-40. REMOVAL. To remove the starting motor from the engine, first disconnect the ground cable from the
battery post to prevent short circuiting. Disconnect the lead from the starting motor terminal, then take out the
mounting bolts. The motor can then be lifted off and taken to the bench for overhaul.
11-41. DISASSEMBLY
a. Remove the frame screws from the commutator end head and pull end head and armature from frame Lift
brushes and lock in elevated position with brush springs. Use a puller to remove the end head from the armature.
Use a special bearing puller to remove the sealed ball bearings from the armature shaft.
b. Remove the frame screws that secure the gear housing to the frame. Remove bolts and nuts holding the
gear housing to the pinion housing and separate the two units. Pull the Bendix shaft from the pinion housing. Do
not lose the steel spacer that is located on the pinion end of the shaft. Remove reduction gear, woodruff key and
spacer from shaft.
c. Turn the Bendix pinion until it locks in the extended position. Locate "spirol" pin and use a punch to
remove. Slide drive assembly off the shaft. Do not attempt to disassemble the drive and do not dip it in cleaning
solvent.
d. To remove the roller bearings from the gear housing, use an arbor press and the correct bearing arbor. DO
NOT HAMMER OUT. Each part should be cleaned and inspected for excessive wear or damage. Bearings
should be checked for proper clearance and evidence of roughness or galling. Oil and dirt should be removed
from insulation and the condition of the insulation checked.
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
ELECTRICAL SYSTEM
2D16
