Abstract: An automatic transmission oil filter retainer includes a base portion; a riser portion extending from a side of the base portion; and a retainer portion extending from a side of the riser opposite the base portion and at right angle to the riser portion, the retainer portion extending parallel to and overlaying the base portion. The base portion is dimensioned with a first short side measuring about 0.56 inches, a second short side measuring about 0.5 inches, and a first long side measuring about 1.39 inches. The through-hole has a diameter of about 0.25 inches. The riser portion is inset along a second long side by about 0.06 inches and extends at 90° from the second short side and the second long side by about 0.59 inches. The retainer portion extends at 90° from the riser portion in a direction towards the first long side by about 0.0305 inches.