Spin-on filter with transparent container portion

A replaceable filter assembly for filtering contaminants from liquid coolant used to cool an internal combustion engine, the filter assembly comprising:

• a round end plate of metal material, the round end plate having a threaded central outlet opening coaxial with a central axis of the filter and a plurality of inlet openings disposed in spaced relation around the central outlet opening, the round end plate having a circular peripheral edge surface, an inner surface facing into the assembly and outer surface facing away from the assembly;
• an annular metal cover plate disposed in abutment with the outer surface of the end plate, the cover plate having a peripheral trough extending beyond the peripheral edge of the end plate and displaced in an axial direction away from the outer surface of the end plate;
• a cylindrical filter element disposed proximate the inner surface of the end plate and having a portion thereof urged against the end plate by a coil spring disposed coaxially with said central axis;
• a transparent unitary plastic container having a cylindrical portion, a closed end and an open end, the container fitting over the filter element and extending past the peripheral edge of the base plate, the open end of the container being surrounded by a unitary annular flange extending radially outwardly from the open end, the annular flange having a radially extending annular end surface, an axially extending peripheral surface and a radially extending shoulder, the annular flange being received in the trough of the cover plate and being retained therein by a portion of the trough deformed thereover;
• and
• an annular seal disposed at least between the a first radially extending surface of the trough and the annular end and surface of the annular flange.