Aftermarket Modifications

WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

Cutting the frame behind the rear axle to shorten the frame is acceptable. Mechanical, cutting, electrical cutting or sawing is the preferred method(s). Flame cutting must be avoided. Whenever it is necessary to cut the frame, the sidemember should be cut at an angle of 90 degrees to the longitudinal axis.

For information on cutting of the frames to lengthen the frames or modify the wheelbase, refer to Wheelbase Alterations in this information.

In some cases, specialized equipment such as hoists, winches, lifts, snowplows, pusher and tag axles are added to the vehicle by distributors, installers or dealers. Unless otherwise specified by the customer at the time of assembly, the vehicle is generally equipped with a standard chassis frame and the manufacturer has not made special allowances for the special equipment which is being added.

The addition or installation of this special equipment on the vehicle can significantly affect the loading of the chassis frame. In some cases, it may be necessary to reinforce the frame. Care must be exercised to make sure that the GVW Rating and/or the GAWR (gross axle weight rating) are not exceeded.

Installation of this special equipment may involve State and Federal requirements which affect vehicle certification for noise emissions, exhaust emissions, brake requirements or lighting system requirements. The specialized equipment installer is responsible for the safety and durability of their product and, in addition, is responsible to make sure that the equipment and its installation comply with all applicable State and Federal Department of Transportation requirements and OSHA regulations.

Addition of specialized equipment may have a significant effect on other vehicle components, such as the brake system, steering system or suspension system. Simple reinforcement of the chassis frame may not be adequate to provide safe operation of the vehicle.

In any modification of the chassis frame, the addition of holes, reinforcements, welds, clamps or splices may cause an increase in the local stress in the frame at the point of the modification. These local stress concentrations can significantly affect the life of the chassis frame. The specific effect which the stress concentrator will have on the life of the chassis frame is influenced by the location of the stress concentration, the frequency and severity of the loading and the type of stress concentration. Any modification of the frame may void the manufacturer's warranty.