What's with the car shaking at high speed?

The causes of vehicle jitter when driving at high speed;

1. The surface of the brake disc is uneven and the radial runout is too large. When braking in this way, the contact between the brake pad and the brake disc is loose and tight, and the braking force is large and small, which causes the vibration of the car body, which is more obvious when the brake is lightly stepped on.

2. The wheel alignment data has a large deviation. In particular, the front wheel positioning angle is inaccurate and the toe-in is too large. This situation is that when accelerating, the vehicle feels difficult to control, and the jitter is generally not big, that is, it is awkward to drive.

3. The tire pressure is too high or too low. The higher the tire pressure, the higher the vehicle speed and the more intense the vibration of the vehicle body. If the tire pressure is too low, the car body will feel flickering and wandering.

4. Abnormal tire wear. Due to wheel alignment or rim deformation, the tire surface wear is inconsistent, which leads to vehicle body vibration during driving.

5. The rim is deformed. When the tire is mounted on the rim, even if the tire is deformed, the rim will be deformed, resulting in uneven surface, inaccurate wheel dynamic balance and vibration when driving.

6, shock absorber failure. If the shock absorption fails, the impact of high-speed driving on the tires will be transmitted to the car body without attenuation, causing the vibration of the whole car body.

7, tire dynamic balance problem. For example, after tire repair, rim deformation, abnormal tire wear, and large nails or stones in the tire will destroy the tire dynamic balance.

8. Half axle vibration. This situation is generally caused by the bending of the semi-axle (front-wheel drive) or the transmission shaft (rear-wheel drive), because the bending destroys the dynamic balance of the transmission shaft, and it will produce * * * vibration during operation, mostly at a certain speed, and there is no abnormality above or below this speed.

9. Lock-up clutch problem of automatic transmission. After the torque converter is locked, the power output of the engine and the input of the gearbox become rigid connection. If it cannot be released in time when braking, the gearbox will hold the engine and cause vibration.

10, engine power problem. Generally, there are ignition and oil supply failures. For example, at high speed and heavy load, the engine power suddenly drops due to insufficient ignition energy, fire or insufficient oil supply of gasoline pump.

1 1. Adjustment of shift points. In order to save fuel, some cars will advance the shift point at high speed, usually the gear above the direct gear (such as the third gear). When the engine is at a low speed, it will shift to a high gear. At this time, the engine will shake slightly due to lack of power. Adding a little oil will pass this speed range, which will not affect driving performance and save fuel.