Parts Replacement & Testing: Commutator

Clean contact surface and polish with fine sandpaper if required. If surface is scored, burned, out of round or pitted, dress in a lathe only enough to restore smooth concentric surface. Out of round should not exceed 0.016" (0.4 mm) on Subaru and 0.012" (0.3 mm) on all other models. Mica depth should be 0.016 - 0.031" (0.40 - 0.80 mm) standard with a limit of 0.008" (0.20 mm). If beyond limit, undercut with a hacksaw blade to standard depth.