A vehicle crossmember assembly including a pair of main rails, a crossmember, and a pair of pedestals is provided. The main rails are laterally spaced apart. The crossmember is transverse to the main rails. The pedestals extend between and connect lateral ends of the crossmember to the main rails. Each pedestal has a lower end disposed adjacent to the crossmember and an upper end that projects upwardly from the crossmember. Fasteners connect the pedestals to the main rails. Each pedestal has a sleeve disposed at the upper end. Each sleeve has a sleeve wall defining a bore that receives one of the fasteners and each sleeve has a slit in the sleeve wall. Each slit provides a release path through which one of the fasteners can pull through the sleeve wall during an impact event, allowing the pedestals to detach from the main rails.