Starting Motor Removal And Disassembly; Brushes Check; Armature Check - Piper PA-24 Comanche Service Manual

PIPER COMANCHE SERVICE MANUAL
9-'78. Ov.rhaul. U dUMg the above inspectiCll
any
indication of st..cine motor difficulty is
noted. the
SUrting
raotor should be remond from the enaine for cleanifte and Npair.
9-'79. RefttO¥al. To remove the startine motor frOal the enliDe, first disconnect the lI'ound cable
from the bettery post to prevent short eireuitiftl. Discoanect
the
Iud from the starting motor
terminal, then take out the 1D000ting bolts. The lIIoter can then
be
lifted off and taken to the
bench for overhaul.
9-80. Dilu.e...
1
r-
a. Remove the frame screws frem the cDlllmutator end hem and pull end h.,d and armature
from frame. Lift the brushes and lock in elevated pc*itioD with brush sprinls. Use a puller to
re-
move the end head from the armature. U.e • special
bearinC
puller to remove the sealed ball
beMrinl from the armature shaft.
b.
Remove the frame serews that secure the par houinC to the frame, Remove bolts and
nuts holding the par houainl to the pinion bausinc and sep. .te the two
WlitS.
Pull Bendix shaft
from pinion housinl, Do not loae'the .t..l spacer that i. located
Oft
the pinion end of the shait.
Remove reduction lear, woodruff key and .teel .pacer from
shah.
c. Tum the Bendix pinion until it locks in the extended po.ition. Locate "spirol" pin and
use a punch to remove. SUd. drive assembly off the shaft.
Do
not attempt to disassemble the
drive and do not dip it in cleaninc solvent.
d. To remove the roller bearincs from the par heusinl, u.e
an
arbor press and the correct
bearing arbor. DO NOT HA."dMER OUT. Each part should be cleaned and inspected for excessIVe
wear or damage. Searinls should
be
checked for proper clearance and evidence of touahness or
lalling.
Oil
and dirt should
be
removed from Wlulation and the conditiCll of the insulation. checked.
9-81.
Brulh...
Check the brushes to see that they slide freely in their holders and make full
contact on the commutator. If worn to half their oricinal lencth or Ie.., they should be replaced.
9-82. Armature.
a. Check the commutater for uneven wear. excessive puine or evidence of excessive arcing.
If only sliChtly dirty, &lueci or discolored, the COllllDutator can be cleaned with 00 or 000 sand-
paper. If the commutator is rOllah or worn, it should
be turned iD a latbe. Refer to Fil\lre 9·29b.
The armature shaft should be inspected for roup bearial sudac:e. and rOUlh or damaged splines.
b. To test the armature for crounds, a set of test probes connected in seri.s with a llQ-volt
light should be used. Touch one probe to a commutator see_nt and the other to the armature
core. If the test lamp lichts. the armature
i. Ctollftded cd should
be
replaced.
c. To test for shotted armature coil., a Itowler i. used. (Refer to Fipte 9-291:.) The arma-
ture is pllCed on the crowler and slowly rotated
by
hand while a steel strip is held over the COM
50
that it
passes
over each armature core sl«.
If
a coil is shorted. the steel sttip will vibrate.
d. A quick check for opens can
be
made by inspec:tinC the tramnl edge
(in
directlon of ro-
tation) of the commutator segments for excessive discoloration. This condition indicates an. open
cireui«.
ELECTRICAL SYSTEM
ISSUED: 8/18/72
3 C16
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