A hub adapted to support an electromagnetic clutch and a hydraulic pump thereon is disclosed. The hub is generally hollow and cylindrical in shape, including a first annular mounting portion having an inner cylindrical mounting surface. The inner cylindrical mounting surface is sized to receive and precisely position therein a cylindrical flange of the hydraulic pump. The hub also includes an enlarged cylindrical flange portion disposed adjacent to the first mounting portion. A plurality of apertures are formed through the flange portion for securing it to an external mounting bracket. The hub further includes a second annular mounting portion having an outer cylindrical mounting surface. The outer cylindrical mounting surface is sized to receive and precisely position thereon a bearing assembly of the electromagnetic clutch. Thus, the hub provides precise co-axial mounting surfaces for both the hydraulic pump and the electromagnetic clutch. By mounting the hydraulic pump and the electromagnetic clutch in this manner, the rotational axes of the components thereof are precisely maintained co-axial during use.