Not necessarily. In fact, industry experts warn that tightening gear tolerances is often used as a “crutch” by engineers who lack the experience to diagnose the root cause of a gear problem. When a gear exhibits noise or vibration, the first question should be whether the part was actually manufactured poorly, or whether there’s a fundamental issue with the design itself—such as incorrect tooth geometry, inadequate contact pattern, or improper mounting alignment.
Many shops cannot adequately check their own parts or monitor tolerances, so they may not even be able to tell if a gear was manufactured to spec. Tightening tolerances without understanding the actual issue drives up manufacturing costs significantly (each step up the DIN/AGMA quality scale typically adds 15-35% to unit cost) and extends lead times due to additional grinding, lapping, or honing operations. The tolerance class should map directly to the functional requirements (backlash, transmission error, noise) rather than being a default carried over from a previous project. Often, problems like noise can be solved more effectively through tooth profile modifications (e.g., crowning or tip relief) or better lubrication, not by tightening all dimensional tolerances across the board.