Interpretation ID: aiam1627
Jr.
General Attorney
Trailmobile
200 South Michigan Avenue
Chicago
IL 60604;
Dear Mr. Lungren: This responds to Trailmobile's September 27, 1974 request for determination that the combination of a new trailer main body structure (underframe, floors, side walls, and nose structure) with the rear doors, lighting components, running gear, and landing gear of a used trailer, would not constitute the manufacture of a new motor vehicle subject to Federal motor vehicle safety standards. You request this determination because motor vehicles manufactured after January 1, 1975, must comply with Standard No. 121, *Air brake systems*.; Re-use of components from an existing vehicle in the construction o another vehicle may or may not result in the manufacture of a new vehicle. The NHTSA has established that the addition of new components (such as a truck body) to the chassis of a used vehicle does not constitute the manufacture of a new vehicle. Conversely, the addition of used components to a new chassis which has never been certified in a vehicle constitutes the manufacture of a new vehicle subject to the safety standards in effect for that vehicle class on the date of manufacture. This criterion has been relied on in the area of chassis-cab multistage manufacture.; Since Trailmobile plans to utilize a new underframe as well as a ne upper structure in the construction of these trailers, we consider that the operation you describe constitutes the manufacture of a new motor vehicle for purposes of application of the safety standards, and Standard No. 121 applies to those trailers manufactured by this process on or after January 1, 1975. To conclude otherwise would mean that re- use of running gear assemblies and rear doors could indefinitely exempt a vehicle from upgraded and newly-issued safety standards.; Yours truly, Richard B. Dyson, Acting Chief Counsel