A viscous type vibration damper is mounted on the front end of the crankshaft to reduce torsional vibrations to a safe value.
Prior to April 1993, 11.1 liter engines with less than 320 hp (238 kW) were equipped with a 313.4 mm (12.34 in.) damper and 11.1 liter engines with 320 hp (238 kW) or more were equipped with a 342.9 mm (13.5 in.) damper, and all 12.7 liter engines, were equipped with a 342.9 mm (13.5 in.) damper.