Analysis of the known technical solutions for the additional loading of tractor from the trailer has shown that they are ineffective. Their ineffectiveness is the complexity of the design and construction of interfering in hydro-mounting construction of tractor or trailer hitch frame. Also, reasonable reloaded on tractor hydromounting is not provided. In order to avoid these shortcomings towing additional loading device to the trailer with a hydraulic cylinder mounted on the frame of the trailer rotatable carriage was suggested. The tests showed that the maximum additional loading of the tractor from the trailer can not exceed 3900 N, which is not sufficient from the position of improving performance.