Motor truck

A motor truck comprising a frame device, a body device movable relative to the frame device, bolt members extending vertically at opposite sides of said frame and body devices to hold said devices together, and an energy transforming means including a first plate member fixed to one of said devices and having an inclined first sliding surface and a second plate member fixed to the other of said devices and having a second sliding surface which slidably contacts with at least a portion of said first sliding surface and is inclined at an angle complementary to said first surface, said body device being moved upwardly by said energy transforming means when a longitudinal impacting force of or greater than a predetermined value is applied, and at least one shear plate fixed between said body and frame devices and adapted to be sheared by said longitudinal impacting force, but normally limiting the relative movement of said devices, said first and second sliding surfaces being linear.