Chapter 9 Electrical System
3. Starter Motor
i
4LHA Series
6
Inspection
6.1
Armature
(1) Commutator
Inspect the surface of the commutator. If corroded or
pitted, sand
with
#500
~
#600
sandpaper. If the
commutator is severely pitted, grind it to
within
a surface
roughness
of at least 0.1 mm (0.0039 in) by
turning
it on a
lathe.
Replace
the commutator if damage is irreparable.
Sand
paper
Model
SI
3-41A
Maintenance
standard
Wear
limit
Commutator
outside diameter
038(1.4961)
036.6(1.4409)
Deflection
Repair
limit
0.1 (0.0039)
Repair
accuracy
0.05(0.002)
(2)
Mica
undercut
Check
the mica undercut, correct
with
a hacksaw
blade
when the undercut is too shallow.
Bad
Hacksaw
blade
Good
Hacksaw
blade
Commutator
Commutator
Segment mica
FaCi
"
9
0.5 ~ 0.8 mm
Bad
Good
mm (in.)
Maintenance
standard
Repair
limit
Mica
undercut
0.2
(0.0079)
0.5 ~ 0.8
(0.0197 ~ 0.0315)
(3)
Armature shaft outside diameter
Measure
the outside diameter of the armature shaft at
four
locations:
front,
center,
end,
and pinion.
Replace
the
armature if the shaft is
excessively
wom.
Check
the bend of the shaft; replace the armature if the
bend
exceeds
0.08mm
(0.0031
in)
mm
(in.)
Maintenance
standard
Repair
limit
Armature shaft
diameter
Front side 025(0.9843)
024.90(0.9803)
Armature shaft
diameter
Rear
side
012(0.4724)
011.90(0.4685)
(4) Armature coil continuity and ground test
Using
a tester, check for continuity between the
commutator and the shaft (or armature core). Continuity
indicates
that
these points are grounded and
that
the
armature must be replaced.
Checking
commutator for insulation defects.
Kind
oftest
Checkpoint
Normal
Abnormal
Continuity
Commutator
between armature
YES
NO
(Broken or
disconnected
coil)
Insulation
Commutator
between armature
or shaft
NO
YES
(Short-circuit)
9-12
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