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.