NON-METALLIC REPLACEABLE FILTER

A plastic oil filter comprises a cup-shaped shell with an open end. The shell contains an annular filter media with an elongated opening therethrough. A backplate is positioned in the open end of the shell. An elongated core is positioned in the opening in the filter media. The core is hollow and has a plurality of openings in the walls thereof. A plurality of longitudinally spaced annular rings are formed on the outer surface of the core. Fluid to be filtered can pass through openings in the backplate into the space between the shell and the filter media, through the filter media to be filtered, through the openings in the walls of the core, into the flow passage in the core, and exit from the filter through the flow passage in the core. Sealing washers are provided at each end of the filter media for preventing undesired flow between the core and the ID of the respective sealing washers. Spring structure is formed on the core. In one embodiment, the spring structure functions to bias the sealing washers with respect to the filter media to better seal fluid flow about the ends of the filter media. When assembled, the spring structure enhances the seal between the core and a filter base.