Abstract: A hydrostatic transmission drive pump swash plate control including a control arm and a cam which are mounted on axes perpendicular to one another. The control arm is connected to the swash plate to effect simultaneous movement of the control arm and swash plate. Cushioned link means operatively interconnect the cam and a manual control member. The cam includes a cylindrical portion with a cam slot which is shaped similar to the first 90.degree. of a sine wave between full speed reverse and neutral and similar to the first 90.degree. of another sine wave from neutral to full forward speed. A resilient cam roller on the control arm absorbs fluctuating stroking forces of the pump and cooperatively engages the cam slot to produce a low rate of ground speed change near the neutral condition of the hydrostatic transmission and also near maximum forward and maximum reverse ground travel speed.