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Technical Rules Bulletin...The axle housing must be of the “closed tube” design utilizing “full floating” magnetic steel axle shafts. The center section of the axle housing must be manufactured of either aluminum or magnesium. Axle tubes must be one (1) piece. Axle tubes must be manufactured of aluminum or magnetic mild steel. Axle tubes manufactured of exotic heavy materials (ex: tungsten) will not be permitted. The outside diameter of the axle tubes must not exceed three (3) inches. Axle tube internal inserts or external sleeves will not be permitted. The addition of any ballast weight to the axle housing will not be permitted.
