A differential wheel mounting for replacing a standard railroad axle assembly having a wheel seat portion which includes a sleeve having several sliding surfaces fixedly mounted over the wheel seat portion of the axle, a railroad wheel with a running surface for contacting a rail and a plain bearing member detachably mounted to the railroad wheel. The plain bearing member has non-metallic bearing surfaces that mate with the sliding surfaces on the sleeve so that the bearing member and the attached wheel are laterally confined on the sleeve while being rotatable about the sleeve. The plain bearing member sustains both radial and thrust loads during normal operation of a railroad car.