What causes the steering wheel to shake when the car reaches 100 mph?

[JonathanDella]

Car reaches 100 mph steering wheel shake reasons are: 1. Dynamic imbalance of the two front wheels; 2. Loose ball joints of the steering linkage. The solution is to perform wheel dynamic balancing after each tire replacement, and check for loose ball joints in the steering linkage during maintenance. If the steering wheel shakes when the car is driven between 80 km/h and 90 km/h, and returns to normal when the speed exceeds 90 km/h, this is mostly due to deformation or issues with the vehicle's drivetrain. It is necessary to check whether the front wheel alignment angles and toe-in meet the requirements, and adjust if they are out of specification. The solution is to lift the front axle and test the wheels, check the static balance of the wheels and whether the tires are excessively deformed. If deformed, they should be replaced.