The authors present the results of experimental rig study on resistance forces in a rack and pinion steering system without power assistance of a small car with MacPherson front suspension. The influence of a harmonic steering angle excitation, with frequency ranging from I to 3 Hz, and different wheel load conditions on self-returnability, sensitivity, and friction forces in the steering system is studied. These characteristics are responsible for the car directional stability at high-speed of cruising or during braking maneuver, and influence comfort, effort, and good feeling of the car driver. On the basis of experimental results, some parameters (equivalent moment of friction forces and stiffness coefficients) of a simplified model are estimated for different excitations and load conditions.