What causes gear clatter?
Gear clatter occurs when the tooth flanks in the transmission separate and hit each other again in actual operation. This is caused by irregularities of torque and of rotation. The possibility of tooth flanks to separate is due to the backlash required for compensating tolerances and thermal expansion to ensure the operational safety of the transmission. As a rule, gear clatter is the result of an unfavorable interaction of individual components, such as engine, couplings, gears, propeller shaft, and propeller. Such influences are beyond the control and responsibility of transmission manufacturers. A distinction should be made between gear clatter under load and idle gear clatter: Gear clatter under load may occur at a specific RPM. It is caused by design factors, such as number of cylinder, number of propeller blades, engine speed, and number of gear teeth. These may incite natural frequencies of the drive unit to such an extent that tooth flanks separate off and clatter despite their
