An apparatus for data transfer with a magnetic disk having a diameter of, say, 86 millimeters, having a pair of transducer heads for data transfer engagement with the opposite surfaces of the disk mounted on a turntable driven directly by a disk drive motor. In order to hold the magnetic disk exactly level on the turntable for proper data transfer contact with the transducer heads, a leveling mechanism is provided whereby at least the turntable is made adjustably movable in its axial direction with respect to the frame of the apparatus, as by the manual turn of an adjusting screw or screws. In one embodiment, the turntable is movable with a drive spindle on which it is mounted coaxially and which forms an output shaft of the disk drive motor. In another embodiment, the turntable travels with the complete disk drive motor.