S.C. Code Regs. 38-393.201. Frames

(a) The frame of every truck and truck tractor shall not be cracked, loose, sagging or broken. (b) Bolts or brackets securing the cab or the body of the vehicle to the frame must not be loose, broken, or missing. (c) The frame rail flanges between the axles shall not be bent, cut or notched, except as specified by the manufacturer. (d) All accessories mounted to the truck tractor frame must be bolted or riveted. (e) No holes shall be drilled in the top or bottom rail flanges, except as specified by the manufacturer. (f) Field repairs are allowed.