Abstract: An apparatus tests rack teeth of a rack member for a rack and pinion vehicle steering gear. The apparatus comprises a support for mounting the rack member for longitudinal displacement and a helically toothed test pinion member having an axis. A carriage mounts the test pinion member for rotation about its axis and in driving engagement with the rack member. A resilient biasing spring urges the test pinion member into engagement with the rack member and provides a predetermined lateral spacing between the longitudinal axis of the rack member and the axis of the test pinion member. A screw adjusts the biasing force of the resilient biasing spring at the predetermined lateral spacing. A drive effects displacement of one of the rack and test pinion members to impart displacement to the other of the rack and test pinion members.