The authors present the experimental results proving that in the real exploitation of a vehicle or a tractor self-exciting oscillations do not occur in friction pairs of friction clutch. This refers to friction clutches with asbestos, asbestos-free polymer and sintered powder friction pads.

The authors propose new schemes of steering mechanisms of tracked vehicles made ​​on the basis of units and components of automobiles. The mathematical model of the steady turning of tracked vehicles with such steering mechanisms are developed as well as methods for calculating kinematic parameters, power and energy loading of the elements in the scheme taking into account the power losses in the transmission and suspension. The accuracy of the mathematical models is confirmed by the results of field tests of a tracked crawler "Vegus" with the proposed schemes of steering mechanisms.

The article presents the results of researches conducted with the use of computer that allow to estimate the influence of tractor unit parameters on possibility of self-excited oscillations of wheeled tractor frame in the case of its moving under load that causes significant slipping of driving wheels.

Findings of investigation of vibration loading of a motor cultivator are given. The cultivator was tested as a part of transport and soil cultivating aggregates on artificial track, concrete road and fertilized soil. Level of vibration on operator seat and on steering wheel in dependence on different tire types, different inner air pressure in the tires and speeds was compared to standards.

Possibility of self-excitation of wheeled tractor frame oscillations in longitudinal plane during the operation in tractive mode is theoretically substantiated. Dependence of rolling radius of a pneumatic wheel on vertical load and on driving moment level, mathematical model describing pneumatic wheel rolling under variable vertical load and two-mass lineal model describing tractor frame oscillations in longitudinal plane are used.