A seal assembly is for a shaft rotatable about an axis, having an outer circumferential surface and being disposed within a housing having an inner circumferential surface defining a bore. The seal assembly includes an annular base member having an outer circumferential surface and a central opening for receiving the shaft with clearance, the base member being sized such that the base outer surface is engageable with the housing inner surface to form an interference fit to retain the seal assembly. An annular seal member is disposed on the base member and has an inner circumferential sealing surface for sealing against the shaft outer surface and an outer circumferential sealing surface for sealing against the housing inner surface. A support member includes a one-piece annular body, is disposed generally between the seal member sealing surface and a portion of the base member, and prevents axial deflection of the sealing member.