The phenomenon of shimmy when the car is driving at high speed: when the car is driving at high speed or at a high speed, it appears unstable driving, swinging head, and even shaking of the steering wheel.
Causes of vehicle high-speed shimmy:
1、 Misalignment of front wheel alignment angle and excessive toe in;
2、 Low front tire pressure or dynamic imbalance caused by tire repair;
3、 The number of tire bolts of front wheel is different;
4、 Loose installation of transmission system parts;
5、 The transmission shaft is bent and dynamically unbalanced; Front axle deformation;
6、 The alarm reducer fails, and the stiffness of the front leaf spring is inconsistent; The cutter frame is deformed, the rivets are loose or the front axle is deformed.
Diagnosis and troubleshooting of vehicle high-speed shimmy fault:
1、 There are two cases of high-speed shimmy: one is that the shimmy becomes stronger with the increase of vehicle speed; Second, shimmy occurs at a higher speed. When the steering wheel shakes, first set up the drive axle, plug the safety plug on the front wheel, start the engine and gradually shift to the high gear to make the drive wheel reach the final test shimmy speed.
If the body and steering wheel shake at this time, it is the vibration caused by the transmission system. Because the front axle of the front wheel is at a standstill at this time, if the final test shimmy speed is reached and the vehicle does not shake, the cause of the shimmy is the fault of the front axle of the vehicle;
2、 Check whether each positioning angle and angle of the front wheel meet the requirements. In case of misalignment, adjust it;
3、 Put up the front axle and test run the wheel to check the static balance of the wheel and whether the tire is deformed too much. If necessary, replace good wheels for comparative test;
4、 Check whether the front axle and frame are deformed and whether the transmission shaft is bent. If possible, make dynamic balance of the transmission shaft;
5、 Check the rigidity of the front leaf spring, the efficiency of the shock absorber and whether the rivet of the spring support is loose. If the performance does not meet the requirements, replace it