List common signs of a failing bearing.

• A. Excessive noise, heat, vibration, rough rotation, and visible wear or scoring on races.
• B. No symptoms are observed despite failure.
• C. Only a slight wobble is observed.
• D. The bearing becomes quieter over time.

Answer: (A)

A bearing failure shows up through a cluster of signs that reflect increased friction, worn surfaces, and misalignment. Excessive noise happens because worn races and rolling elements create impacts and irregular contact, producing grinding or squealing sounds. Heat indicates lubrication problems or higher friction, which quickly raises the bearing’s temperature. Vibration increases as the bearing loses smooth rolling action and the shaft experiences uneven loading, often becoming detectable as higher overall vibration or at characteristic frequencies. Rough rotation means the bearing doesn’t turn smoothly, feeling stiff or gritty when you rotate the shaft. Visible wear or scoring on the races is a direct sign of surface damage from wear, debris, or spalling, confirming the component is degraded.

If there were no symptoms, you wouldn’t have evidence of failure, and a slight wobble or a quieter bearing doesn’t align with ongoing wear and damage. When you observe this combination of noise, heat, vibration, rough movement, and visible wear, it points to a failing bearing that needs immediate inspection and likely replacement or lubrication and alignment corrective actions.