Abstract: A grille unit has a frame and a vane pivotally connected to the frame via opposing first and second shafts. The frame has first and second holes snugly receiving the first and second shafts respectively. The first shaft has a peripheral surface, the diameter of which continuously varies along the axis thereof. The second shaft has a similar peripheral surface. The varying-diameter surfaces of the first and second shafts face in opposite directions. The frame has a first inner surface which conforms to the varying-diameter surface of the first shaft to engage the latter. The frame has a second inner surface which conforms to the varying-diameter surface of the second shaft to engage the latter. A method of manufacturing the grille unit includes the steps of forming the frame from plastic, and assemblying a mold with the frame positioned within the mold.