The paper reports rather unique research on the influence of freeplay and friction in the car steering mechanism on automatically controlled process of lane change. The developed controller algorithm was based on very simplified (and thus effective in on-line calculations) reference models of the car dynamics, obviously without taking into account the nonlinearities of its steering system. Extensive simulation investigations of the developed controller algorithm carried out in a very wide range of changes in road and operational conditions, with regard to two-axle medium-duty truck, confirmed its advantages. The research presented in this article concerns the unpublished area of analyzes concerning the sensitivity of the lane change controller to freeplay and friction occurring in the steering mechanism of a controlled car. Some results of the simulation tests turned out to be surprising The piecewise-linear luz(...) and tar (...) projections used in these studies to describe the freeplay and friction effects facilitated modeling and simulation calculations.