Bench Testing: Commutator
WARNING: This page is about a different car, the 2004 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
Inspect commutator for roughness, grooves, burns, pitting and out-of-round. If necessary, sand lightly with 500-600 grit sandpaper. If mica insulator undercut is less than .008" (.20 mm), undercut to .020-.031" (.50-.80 mm). Replace armature if commutator diameter is less than specified. See STARTER SPECIFICATIONS .