The problem of the theory of power transmission to wheels of a vehicle, as part of the theory of cars, has always been in the center of attention of specialists. With the improvement of designs of a vehicle there was a need of thorough scientific review of theoretical and experimental aspects of creating and applying of mechanical, hydrostatic, electrical, and combined transmissions. This has always remained one of the most important questions of the rational allocation of power among drive wheels.
In the present paper, it has been done study of different methods of power distribution among the drive wheels of an all-wheel-drive truck, namely: method of partial solution; method of introducing a rigid kinematic connection; method of periodical action; and method of limit of excessive action. Assessment how these methods influence on the performance characteristics of a multi-purpose vehicle has been done.
For implementation of the method of partial solution it has been developed method of measuring of rational gear ratio of center differential providing the required level of performance of the all-wheel drive truck. For implementation of the method of periodical action the appropriateness of switching off some of the driving axles is justified. Assessment of the effectiveness of the method of limit of excessive action by applying a braking torque to the slipping wheels has showed that the degree of braking is limited, on the one hand, by exception of slipping of the wheels on the surface with worse traction, and, on the other hand, by providing sustainable drive of the all-wheel-drive truck. Using the method of limit of excessive action by controlling engine torque with simultaneous introduction of rigid kinematic connection is the best way to increase the mobility of all-wheel-drive trucks in conditions of compacted and loose soils. The made studies that are described in this paper will help designers to find the best way for design a system of power distribution in transmissions of all-wheel-drive trucks.