Which option best completes this statement: Gear, drive, or motor irregularities can cause which phenomenon?

• A. Ambient temperature fluctuations
• B. Lubricant viscosity changes
• C. Gear, drive, or motor irregularities
• D. Electrical supply voltage stability

Answer: (C)

Gear, drive, or motor irregularities cause uneven torque transmission. When parts don’t mesh or rotate smoothly—due to wear, misalignment, backlash, or imbalance—the forces applied each turn are not uniform. Those abrupt, periodic impulses excite the machine structure, leading to observable vibration and noise. If these irregularities aren’t addressed, wear accelerates and the system can degrade further.

Ambient temperature fluctuations are environmental and affect clearances through expansion; changes in lubricant viscosity alter lubrication film and friction; and electrical supply voltage stability affects motor performance. These factors can cause other issues, but the direct phenomenon produced by gear, drive, or motor irregularities is the mechanical vibration and noise they create.