When is excessive heat indicated as a possible cause of bearing wear?

Excessive heat in a bearing can lead to various issues, primarily wear and degradation of the bearing material. Discoloration of the bearings to blue is a direct indicator of this heat issue. The blue color indicates that the metal has reached a high temperature, sufficiently altering its properties.

In a well-functioning system, bearings should maintain their original appearance. The appearance of a blue color suggests that the temperature has reached a critical point, leading to potential failure due to oxidative wear or loss of lubrication properties. Monitoring for such discoloration can therefore serve as a vital diagnostic tool for technicians assessing bearing integrity and overall system health.

The other options speak to different issues—tight bearings might cause friction but don't directly indicate excessive heat. Water in the lubricant can contribute to other forms of damage, such as corrosion, not necessarily directly linked to heat. Noise from gears typically suggests mechanical issues like misalignments or damage, rather than heat-related degradation alone.