Standard Alternators: Inspection
Wash all metal parts except bearings, stator and rotor. Inspect rotor slip rings, and clean with 400 grit or finer polishing cloth. Hold cloth against slip rings and spin rotor to clean evenly and avoid flat spots. Slip rings may be lathe turned to a .002" (.05 mm) indicator reading. Slip rings are not replaceable. Excessive damage will require rotor replacement. Inspect brushes for wear. Clean with acetone if necessary, and replace if excessively worn.