Starter Component Inspection: Commutator
- If commutator surface is dirty or burnt, it can be cleaned with No. 400 grit sandpaper or on a lathe. If commutator runout (out-of-round) is more than .002" (.05 mm), turn commutator on a lathe. Wear or cutting limit of commutator diameter is 1.06" (27 mm) for 0.8 kW starter and 1.14" (29.0 mm) for 1.0 kW starter. If commutator diameter is less than minimum, replace armature.
- Ensure undercut depth between commutator segments are clean, free of debris, and that edges are smooth. Minimum undercut depth is .008" (.20 mm). If undercut depth is less than minimum, use a hacksaw blade to correct to a depth of .008-.024" (.20-.60 mm).