Nowadays, the cares with the vibration and the demands with the comfort of self-driven vehicles became basic requirements to the acceptance of a new truck market project more competitive and optimizing solutions that reduce the problems with vibration and comfort. Inside of those, an evaluation of commercial prototype vehicle of medium load will be presented in this work, searching to reduce a flaw still detected on test phase. Measures as change of shock cabin absorber, changes of tires, system of stabilizer bar at the back axis, changes of the front springs and use of linked shock absorber to the mount of the engine will be presented. Evaluations, which were done initially in the vehicle, the diagnosis was the movement happened due to resonance that includes the flexural of the frame, associated to the movement of pitch of the power train and of the cabin. Significant reductions were reached at three directions: longitudinal, transverse and vertical using the measures mentioned above. At this preliminary phase, the evaluation measures improved the number of hours for the condition of driver's comfort, giving to the vehicle, better acceptance for the proposal and quality of final project.