Shut the turbine down if which condition is present on the gear teeth?

• A. Cracks in the gear teeth
• B. Wear on teeth
• C. Flaking and/or Marco-pitting
• D. Lubricant leakage

Answer: (C)

Gear teeth rely on a solid, continuous surface to carry high loads. When flaking or macro-pitting appears, large areas of the tooth surface are breaking away due to fatigue. This isn't just surface roughness—the material is being removed in chunks, which drastically reduces the tooth’s strength and mesh integrity. Under load, a tooth with flaking or macro-pitting can quickly fail, potentially causing cascading damage to gears, bearings, and the turbine system. That combination of rapid deterioration and high risk of sudden fracture is why shutting the turbine down at this sign is the safest choice.

Cracks indicate a fracture path but may be localized and detectable through inspections, wear is often a gradual loss that can be monitored or limited within tolerated limits, and lubricant leakage points to lubrication issues that, while serious, do not on their own show the same immediate, high-risk fatigue damage to the gear teeth.