Remove the frame and lay it flat. Pass a steel wire through the center of the front and rear beams of the frame. When adjacent channel beams cross each other, the distance between the two intersections and the center line should not be greater than 3mm, and the length difference between H and L2, %3 and %4,% and should not be greater than 3mm, so U must be corrected. Processing method of frame deformation: 1. For a truck that often travels on mountain roads or country roads with a mileage of more than 6,543,800 kilometers, we may find signs such as broken frame, heavy steering, abnormal tire wear and deviation during inspection (these phenomena are generally precursors of frame deformation); 2. For ordinary cars, the frame is the foundation of the whole car, bearing and fixing most parts and assemblies of the car, such as engine, transmission system, suspension, steering system, cargo box and so on. They all rely on the framework to play their corresponding functions. Generally speaking, overloading of vehicles on roads with large height difference is the main reason for frame deformation. Due to the different vertical positions of vehicle wheels, the frame will be deformed, which will lead to the distortion of the frame and produce certain plastic deformation; Or when the car is running normally, one side of the front wheel is subjected to great resistance, which leads to the deformation of the diagonal plane of the frame; When a car collides, it will also cause the deformation of the frame to varying degrees; In the process of use, due to improper traction, the car fell into a mud pit and other conditions, leading to rollover accidents, which is also one of the main reasons for the deformation of the frame; 3. For serious frame deformation, it can generally be directly detected, which is convenient for timely elimination; Once the frame is deformed, you should go to a professional garage for repair as soon as possible. Generally, the basic method is to disassemble the whole vehicle, reshape it or replace the corresponding parts and then rivet it again. For serious frame deformation, the frame assembly should be replaced as soon as possible to completely eliminate this hidden danger; As for the broken frame fault, it is easy to find it when we check the car regularly. As for cars that drive on roads with poor road conditions all the year round, check more. Once the frame is broken, it should be welded or riveted again. When welding, the materials should be consistent, otherwise the welding quality is difficult to guarantee and the joint is likely to break again.