Mitsubishi diesel engines, Service Manual

Page: 172 / 219

ELECTRICAL SYSTEM - DISASSEMBLY, INSPECTION AND REASSEMBLY
7 - 13
(2)
Inspecting the armature
(a)
Using a dial gauge, measure the commutator
for radial runout. If the measure value is equal
to or exceeds the limit, correct (within the
diameter limit) or replace.
Unit: mm (in.)
Standard
value
Limit
M001T68281
0.05
(0.002) Commutator
radial runout M008T70471A
M008T81071A
0.03
(0.001)
0.10
(0.004)
(b)
Measure the commutator diameter.
If the measured value is equal to or less than
the limit, replace.
Unit: mm (in.)
Standard
value
Limit
M001T68281
29.4
(1.16)
28.8
(1.13) Commutator
diameter
M008T70471A
M008T81071A 32.0
(1.26)
31.4
(1.24)
(c)
Measure the depth of undercutting between the
commutator segments.
If the measured value is equal to or less than
the limit, correct or replace.
Unit: mm (in.)
Standard
value
Limit
Mica
undercutting
depth M001T68281
M008T70471A
M008T81071A
0.5
(0.02)
0.2
(0.01)
(d)
Armature coil short circuit
Using a growler, test the armature coil for
short circuit. Replace if short circuit is
indicated.
How to inspect: (Before inspection, remove any
debris from the armature coil.) With
a thin iron plate positioned parallel
with the armature coil, slowly rotate
the armature coil. While the coil is
running, the iron plate should not be
pulled onto the coil or vibrate.
Measuring the commutator radial runout
Commutator
Measuring the commutator diameter
Measuring the mica undercutting depth
Testing the armature coil for short circuit
Diameter
Undercutting
Segment
Mica
Growler
Iron plate