Vehicle category: trucks.system: wheels; malleable iron hubs, part nos. 333-Q-2383, t-2438, and c-2551.consequences of defect: the hub will be retained on the axle spindle followingfailure, but continued vehicle operation will result in separation of the hub,wheel, and tire from the vehicle. This could cause loss of vehicle control andan accident.note: warnings of hub failure include wheel wobble, shimmy, or front wheelvibration.