For critical drives a quick visual and hearing inspection should be performed periodically. A visual and hearing inspection consists of the following three items:
1. Look and listen for unusual noise and vibration while observing the drive.
2. Inspect the guard for loose parts and damage. Make sure it is clean. Any accumulation of foreign material on the guard acts as insulation and could cause excessive heat buildup in the drive.
3. Look for oil and grease contamination that could degrade the material components of a belt.