Abstract: An oil-filter assembly has an upwardly open can generally centered on an upright axis and having at an upper rim a mounting ring having in turn an axially upwardly directed annular seal surface and, offset axially downward therefrom, an annular upwardly directed annular shoulder surface. A filter insert of filter material in the can has an annular outwardly directed flange sitting on the shoulder surface and an upper end wall. A cover fittable over the ring has a lower surface engageable with the seal surface of the ring and with the end wall of the filter insert. Fasteners press the cover down on the ring and filter insert and retaining the cover in place on the ring.