The screw jack is a device for lifting heavy loads by applying comparatively small at its handle. The common problem faced in the conventional screw jack is that it requires great efforts to raise or lower the load. For heavy goods carrier vehicle, this jack is not useful and hence hydraulic jack is preferred which is costly. Today’s requirement of jack is that it should require low effort and low cost so the ‘Modified Jack’ is compromise between hydraulic jack which is costly and conventional screw jack which requires high effort for heavy load. The design of this screw jack to reduce man power, to increase the efficiency, to reduce the work load, to reduce the production cost, less maintenance.