Starter Component Inspection: Commutator

Using "V" blocks and dial indicator, check commutator runout (out-of-round). Ensure runout is not more than .002"(.05 mm). Turn commutator/armature on lathe until runout (out-of-round) is within specification.
Check diameter commutator. Commutator should not be less than specification. See MINIMUM COMMUTATOR SPECIFICATIONS table. If commutator is cut down more than .008" (.20 mm), undercut insulating mica to depth of .015-.031" (.38 -.78 mm).