recirculating ball, also known as recirculating ball and nut or worm and sector, is a steering mechanism commonly found in older automobiles, off-road vehicles, and some trucks. most newer cars use the more economical rack and pinion steering instead, but some upmarket manufacturers (such as bmw and mercedes-benz) held on to the design until well into the 1990s for the durability and strength inherent in the design. a few, including chrysler, general motors and lada, still use this technology in certain models including the jeep wrangler and the lada niva.