Gears

^ Inspect the teeth of each gear. If excessively worn, broken or chipped, replace the gear. Excessive wear increases backlash, which results in noise and unacceptable operating characteristics.
^ Some forms of grind marks and tooth wear contact patterns are acceptable and should be considered as a source of gear noise. Grind marks are distinctive from wear damage which are local swells (polished raised projections), nicks and chips. All gears have possible factory repair grind marks. Phosphate-coated gears are especially easy to recognize since the grind operation removes a patch of phosphate and base metal exposing the lighter metallic color.