The movement of the system "tractor - transport-technological machine of variable mass" is considered in the context of the movement of the center of mass of the system, given the equality of the internal forces of this system among them-selves. Using the obtained dependencies, it is possible to determine the effect of changes in the acceleration of the center of mass of the transport-technological unit with variable mass on the load of the tractor's transmission parts. The tractor control algorithm is synthesized in the rational area of transmission elements loading and a program for its implementation in the field is developed. The developed application is an information system, the purpose of which is to inform the operator of the presence of stress in the transmission`s elements of the tractor, which cause it overloading and, therefore, reduce the resource of its parts. If the strength condition for fatigue failure is not met, the operator of the transport-technological unit is offered to change the driving mode to reduce the load on the transmission elements