Section 480.20 - Vehicle combination transporting combustible liquid; requirements; information required to be on file; retention and transfer of information; applicability of requirements in subsections (2) and (3); transport of flammable liquids, gases, or compressed gases(1) A truck tractor pulling a semitrailer and a trailer, or pulling 2 semitrailers, shall not transport a combustible liquid unless the vehicle combination meets the following requirements: (a) Is equipped with a device that restricts the horizontal and vertical rotation of the dolly assemblage of the vehicle combination in a manner that maintains the longitudinal tracking of the dolly and semitrailer in a truck tractor, semitrailer, and trailer combination, or the dolly and the truck in a truck and trailer combination. This device shall be welded to the vehicle in a workmanlike manner, and the efficiency of a weld shall not be less than 85% of the mechanical properties of the adjacent metal in the chassis.(b) Is equipped with stops in the spring hangers of each semitrailer and trailer in the vehicle combination in a manner that improves the stability of the vehicle combination by reducing the free play of the leaf spring suspension to a maximum of 3/4 of an inch when the spring passes from tension to compression.(2) The owner of the semitrailer or trailer to which the device described in subsection (1) is attached shall keep on file in their principal place of business the following information: (a) Specifications and plans of the device.(b) Name of the manufacturer of the device.(c) Date of installation of the device.(d) An individual manufacturer identification number which is stamped or permanently affixed to the device.(3) The information required in subsection (2) shall be kept by the vehicle's owner and shall be transferred to the new owner if the vehicle is sold, or may be destroyed if the vehicle is retired from service or scrapped.(4) The requirements specified in subsections (2) and (3) apply to devices affixed to vehicles on or after the effective date of the amendatory act that added this subsection.(5) Commercial motor vehicles used to transport flammable liquids, flammable gases, or compressed flammable gases shall also comply with section 722a of the Michigan vehicle code, Act No. 300 of the Public Acts of 1949, being section 257.722a of the Michigan Compiled Laws.Add. 1984, Act 23, Imd. Eff. 3/8/1984 ;--Am. 1995, Act 265, Imd. Eff. 1/8/1996.