I've had this problem ever since I replaced the power steering cylinder and control valve. When turning left or right, especially at slow speeds, the wheel shakes in my hands, kind of like a stuttering-jerky motion.
Would this be caused by a bad PS valve or bad cylinder? Or something else?
Actually, it sounds like the pump isn't building enough pressure. Especially at low speeds when the pump isn't being spun quickly. Could also be the belt slipping I suppose which would also result in low pressure.