Abstract: A gear-reducing, torque-multiplying gear drive assembly having a housing journaling coaxial input and output shafts coupled by an orbital gear drive assembly. A driving sun gear is fixed on the input shaft and rotates a plurality of input planet gears fixed to associated planet shafts journaled at their opposite ends by end walls of a rotary cage within the housing. Each planetary shaft also has an output planet gear within the cage enmeshed with a stationary sun gear fixed to the housing. Rotating the input shaft rotates the planet gears which in turn rotates the cage and drives the output shaft. Selecting the output planetary gears and stationary sun gear to be twice the size of the input gears produces a 2:1 gear ratio between the input and output shaft with a resultant 1:4 torque ratio.