A vehicle frame assembly (32), including a pair of sidebars (27), interconnecting crossbars (33, 34, 35) and optional connecting brackets (38) all formed from channel sections, is manufactured using soft adjustable tooling, preferably a roll former, thereby eliminating the need to use hard tooling. The shorter frame assembly components, including the crossbars (33, 34, 35) and optional brackets, are formed as multi-piece gang members. The frame may be assembled with mechanical fasteners (bolts or rivets) or by welding, the latter obviating the need to use brackets. When mechanical fasteners are used, the components are hole-punched, preferably with numerically controlled piercing equipment. When heat treated steel is used, the piercing and cutting operations are preferably performed after heat treating.