Starter (Inner Components) Inspection: Armature

1. Verify that there is no continuity between the commutator and the core at each segment using an ohmmeter. If there is continuity, replace the armature. See Fig 1 .
2. Verify that there is no continuity between the commutator and the shaft using an ohmmeter. If there is continuity, replace the armature. See Fig 2 .
3. Place the armature on V-blocks, and measure the runout using a dial indicator. If not within the specification, runout 0.002" (0.05 mm) maximum, repair using a lathe or replace the armature. See Fig 3 .
4. Measure the commutator diameter. If not within the minimum specification, standard commutator diameter 1.16" (29.4 mm), minimum commutator diameter 1.13" (28.8 mm), replace the armature. See Fig 4 .
5. Measure the segment groove depth of commutator. If not within the minimum specification, undercut the grooves to the standard depth. Standard depth is 0.016-0.023" (0.4-0.6 mm), minimum depth 0.008" (0.2 mm). See Fig 5 .

Fig 1: Checking For Continuity Commutator To Core

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Fig 2: Checking For Continuity Commutator To Shaft

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Fig 3: Measuring Run-Out

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Fig 4: Measuring Commutator Diameter

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Fig 5: Measuring Segment Grove Depth

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