5312. Crossmember. SINGLE REAR WHEEL. A component to which the pickup box Floor pan attaches to. Multi-Purpose Adhesive. Supporting sheetmetal structure attached to the underside of the Floor pan. Center c'member. Extension. MEMBER - Cross. Multi - Purpose Adhesive. Panel below gate. REINFORCED. Reinforcement. Support. Truck Bed Sill. Included with: Bed Floor, Floor pan.