Abstract: Manufacture of brake drums having an annular brake ring and a drum back for mounting the ring for rotation about an axis defined at least in part by one or more openings in the back. Radial runout of the brake ring is measured, and the mounting openings in the drum back are located at a position to substantially cancel the first harmonic of measured radial runout. The radially inwardly directed braking surface of the drum ring is then finish-machined on a cylinder of revolution coaxial with the drum back mounting openings so as to provide a brake ring of substantially uniform thickness and weight distribution about the axis of rotation defined by the drum back mounting openings.

Abstract: A method and apparatus for manufacture of a vehicle wheel rim and disc assembly with controlled lateral runout characteristics in which a preformed rim is fixtured and rotated while gauges measure lateral runout of the inboard and outboard rim bead seats. Phase angle and amplitude of the first harmonic of average lateral runout of the bead seats are determined, which effectively identify a rim plane of substantially zero first harmonic of bead seat lateral runout. The wheel disc is fixtured with its mounting surface, defined by the inboard face of the disc, at predetermined orientation with respect to the rim plane of substantially zero first harmonic of bead seat lateral runout, either parallel thereto for a true running wheel or at predetermined angular orientation with respect thereto for placing the high point or low point of the first harmonic of lateral runout of the rim and disc assembly adjacent to a predetermined location circumferentially of the rim.

Abstract: Manufacture of brake drums having an annular brake ring and a drum back for mounting the ring for rotation about an axis defined at least in part by one or more openings in the back. Radial runout of the brake ring is measured, and the mounting openings in the drum back are located at a position to substantially cancel the first harmonic of measured radial runout. The radially inwardly directed braking surface of the drum ring is then finish-machined on a cylinder of revolution coaxial with the drum back mounting openings so as to provide a brake ring of substantially uniform thickness and weight distribution about the axis of rotation defined by the drum back mounting openings.