The paper deals with the transmission ratio and efficiency determination of a Minuteman cover drive planetary gear train for gears replacement. Two methods are predicted for transmission ratio determination: The Willis method and the alternative torque method. The transformation procedure of one‐carrier planetary gear train into the equivalent two‐carrier gear train to which the torque method can be applied is explained, concluding that the two methods lead to the same results. This procedure may be applied to other types of planetary gear trains with three central gears. The efficiency was calculated by using reference from literature.