Abstract: In a steering angle ratio varying device for a vehicle adapted to be connected in series with a steering input shaft, a first shaft on an input end and a second shaft on an output end are supported in a mutually parallel and laterally moveable relationship, and a crank pin extending from the second shaft is engaged in a diagonal slot provided in an associated axial end of the first shaft. Because the radial distances of the point of engagement between the first and second shafts as measured from the axial center lines of the first and second shafts generally differ from each other, there is a nonlinear relationship between the angular displacements of the first and second shafts.