A recirculating-ball drive has a ball nut centered on an axis and formed with an internal helical groove and receiving a spindle centered on the axis also and rotatable in the nut about the axis. This spindle is formed with an external helical groove of substantially the same pitch as the groove of the nut and having two turns interrupted by a substantially planar flat spaced radially outwardly of the axis. Faces of wedges bolted to the flat define thereon a pair of parallel guide surfaces which in turn define with the flat a passage extending between the interrupted turns of the spindle groove at an angle opposite the pitch angle of the spindle groove. An annular row of like balls fills the passage and the turn of the spindle groove interrupted at both ends by the flat.
