Driveline Optimization to Reduce the Noise in 4X4 Heavy Commercial Vehicle

One of the important factors strongly required by customers nowadays is lower noise and vibration in vehicle. In this paper the prime focus is made on the study of effect of driveline angles on the noise and vibration behavior in a 4X4 configuration commercial vehicle. The impact of propeller shaft angles in the transfer of driveline excitations to the transmission and the resulting noise and vibration is studied. An abnormal noise was perceived from transmission and the root cause was investigated for the same. These excitations were high due to the higher driveline angles as this was design requirement to maintain higher ground clearance. A two-stage approach was adopted to modify the effect (transmission) and cause (propeller shaft angle) there by reducing the abnormal noise and vibration perceived in the vehicle. First the driveline angles were reduced to optimum and secondly, the axle was modified suitably so that the required lower angle of propeller shafts is achieved without affecting the ground clearance. This eliminated the driveline noise and vibration in vehicle. The same was perceived both objectively and subjectively.