Why does the car start to shake when driving at 120 km/h on the highway?
3 Answers
When the car reaches 120 km/h, it is in a high-speed driving state. The shaking that occurs at this speed can be analyzed from the following two dimensions: 1. The vibration gradually intensifies as the speed increases. 2. When vibration occurs at a certain high speed and causes the steering wheel to shake, first lift the drive axle, place safety blocks in front of the front wheels, start the engine, and gradually shift into higher gears to bring the drive wheels to the final test vibration speed. 3. If both the body and the steering wheel shake at this point, the vibration is caused by the drivetrain, as the front wheels and axle are stationary at this time. If the car does not shake at the final test vibration speed, the cause of the vibration lies in the front axle, and further diagnosis and troubleshooting are required.
My car starts shaking when driving at around 120 km/h on the highway, especially noticeable on smooth roads. This is most likely due to improper tire dynamic balance. Unbalanced tires cause the wheels to wobble at high speeds, leading to vibration throughout the vehicle body. Uneven tire wear is also a common factor, possibly caused by incorrect wheel alignment, which results in uneven tread wear. You can check if the tire pressure is appropriate, as both too high or too low pressure can worsen the problem. Also, look for uneven wear patterns on the tire tread. It's recommended to get a professional dynamic balance adjustment done as soon as possible. Typically, this costs only a few dozen to a hundred yuan. If left unchecked, prolonged imbalance can damage the wheel hub bearings, shorten their lifespan, and compromise driving safety, posing risks to others as well. Don't wait for a small issue to become a big one—address it promptly by finding a reliable repair shop. High-speed shaking is not something to ignore.
My car shakes violently when driving at 120 km/h, sometimes even vibrating the steering wheel. Later, I found out that the main cause was a problem with the suspension system. Worn or damaged shock absorbers can't absorb high-speed vibrations, becoming stiff, and loose ball joints can have a similar effect. Signs include more severe bumps when driving over potholes or squeaking sounds. It's essential to inspect and repair immediately. The cost of replacing parts starts from a few hundred yuan but can prevent more expensive damage, such as premature tire wear. Avoiding rough roads in daily driving can slow down suspension wear and ensure comfort on long trips. If you encounter shaking during high-speed driving, don't push through—safety first, pull over and check.
