Why Does the Steering Wheel Shake When the Car Exceeds 120 km/h?

[SanGianna]

The main reasons for steering wheel shaking when the speed exceeds 120 km/h are as follows: 1. Feedback force generated by the contact between the tires and the ground. 2. Inward or outward tilting of the car wheels. 3. Presence of foreign objects on the tire surface. 4. Loss of wheel balance weights. 5. Deformation of the wheel hub. 6. Excessive clearance in the steering linkage. 7. Insufficient tire pressure. Specific issues related to car tires can be divided into the following points: (1) Uneven tire pressure among the four wheels. (2) Uneven tread wear among the four wheels. (3) The wheel rims of the four wheels are not perfectly round. (4) No alignment correction was performed after replacing the tires on the four wheels. (5) A foreign object punctures one of the tires and forms a bulge on the tread, which is not noticeable at low speeds but becomes very obvious at high speeds due to the frequency vibration generated.