Abstract: An anti-blinding grain, seed and like particulate cleaning and grading machine includes a gyrating support frame assembly, and mechanism for vibrating the assembly. Horizontally inclined opposed guide members extend along the side members of the assembly on the interior face thereof at a horizontally inclined angle to project interiorly thereof. The separating screen for separating overs and unders has side rails which are supported by the flanges which project outwardly from the side rails of a clearer ball tray to overlie the guide members. Balls trapped in the ball tray are deflected upwardly with the gyrating motion to engage the separating screen and keep it from becoming blinded. Swingable clamp shoes clamp the screen side rails and the ball tray side rails against the guide members.