A constant velocity or homo-kinetic universal joint transferring torque through at least three ball members between inner and outer coupling members and held by a cage in a common plane bisecting the angle between the axes of thecoupling members. The radial dimension of the joint is kept at a minimum and the cage rides on spherical walls of the inner and outer coupling members and has circumferentially spaced, radial lugs increasing the guide surfaces of the cage windows. The cage is positioned normal to the open face of the outer coupling member, pushed into the coupling member, rotated circumferentially to align the lugs to fit into the grooves of the coupling member, and then rotated axially into the plane of the coupling member to hold the coupling members in fixed axial relation.