The Angle transmission ratio of steering gear can be designed to decrease, increase or remain unchanged.. The main factors that affect the variation of the selected transmission ratio are the load on the steering shaft and the requirement of truck maneuverability.If the truck with small steering axle load or power steering does not have heavy steering problem, a smaller steering gear Angle transmission ratio should be adopted to improve the handling of the truck.If the steering axle load is large, the handling of freight cars is prominent in the sudden turn at low speed, the larger steering gear Angle transmission ratio should be selected..When the truck turns at a higher speed, the steering wheel should respond and the steering gear Angle ratio should be smaller.When the truck is running at high speed and in a straight line, the steering Angle transmission ratio of the steering wheel in the middle position should not be too small.. Otherwise, steering is too sensitive, making it difficult for the driver to control the steering wheel accurately.The Angle transmission ratio curve of steering gear should be roughly in the middle..