Abstract: In a machine tool a bed-slide movable on a guide-way is driven by a motor mounted on the bed-slide and driving a pair of pinions journalled on the bed-slide and engaging racks provided on the bed of the machine tool in a stationary relationship thereto. Imbalance of the torques driving the pinions might interfere with proper guidance of the bed-slide on the bed. Therefore, the driving torques are perfectly balanced by the provision of a differential transmission connecting the motor to the pinions. Preferably, the differential transmission includes a shaft mounted on the bed-slide for axial displacement and a pair of helical gears of opposite hand fixed to said shaft, each helical gear driving one of said pinions.