The mechanical vibration causes health issues to drivers, such as backache, spinal cord injury, etc. In this regard, a tractor engine plays important role. Tractors without chassis are equipped with a balancer unit reducing the secondary engine vibrating force and decreasing the engine and tractor vibration. The paper presented investigates the effects of balancer on secondary vibration. In this research, the root mean square (RMS) of vibration was computed for specific periods of engine work. Effects of rotational speed and engine load on engine vibration in two modes with and without balancer were investigated. The results showed that, at full engine load, increasing the engine speed resulted in increasing the vibration in both observed modes. Balancer utilization reduced the vibration by 22.3% on average. At fixed rotational speed, increasing load caused an increase in vibration in both observed modes. At 1400 rpm rotational speed and 125 Nm torque, balancer utilization managed to reduce the RMS of secondary vibration by 38.9%. Furthermore, at 250 Nm, RMS vibrations were reduced by 21.3% in comparison to no balancer mode. At full load, variable rotational speed, the balancer significantly reduced vibration by 29% on average. The balancer proved to be more efficient at lower torques.