What Causes Steering Wheel Vibration When Car Speed Exceeds 120 km/h?

[MackenzieLee]

The reasons for steering wheel vibration when car speed exceeds 120 km/h are as follows: 1. It is caused by the force feedback generated after the tires come into contact with the ground; 2. A series of issues with the car itself, such as inward or outward tilting of the wheels, foreign objects on the tire surface, falling off of wheel balance weights, deformation of the wheel hub, excessive clearance of the steering linkage, insufficient tire pressure, etc. The specific problems with car tires are divided into the following points: 1. Uneven tire pressure among the four wheels (especially the front two wheels). 2. Uneven tread wear among the four wheels (one-sided tire wear). 3. The rims of the four wheels are not perfectly round (steel or aluminum rims deformed into an oval shape). 4. No alignment correction was performed after replacing the four wheels' tires. 5. A foreign object punctured one of the tires and formed a bulge on the tread, which is not noticeable at low speeds (absorbed by the suspension system), but once driving at high speeds, the resulting frequency vibration becomes very obvious.