Secondary suspension of freight cars has a small number of components, is reliable, cheap to maintain, and has a very traditional design. Despite all these characteristics, its dynamic response is subject to a number of interesting phenomena related to friction damping that are not completely explored for new design of heavy vehicles. This paper describes a new method for modeling this type of mechanical system using a linear complementarity approach for contact calculation. Results presented here show that friction coefficient not only can affect the general damping of the dynamic response to sinusoidal excitation, but also impacts the development of nonlinear phenomena related to stick-slip. These should be taken into account the development of the new generation of freight wagons aiming for increased performance and safety and reduced maintenance costs Ver menos