What could cause steering wheel shimmy?

Steering wheel shimmy is often caused by an imbalance in the wheels. When the wheels are out of balance, it means that the weight distribution on the wheels is uneven, which can lead to vibrations at certain speeds. As the vehicle accelerates, these vibrations become noticeable and can cause the steering wheel to shake or shimmy. This is particularly evident when driving at higher speeds. Proper wheel balancing is essential to maintain smooth operation and to prevent such vibrations.

While low tire pressure, worn ball joints, and poor alignment can all contribute to handling issues and may produce different symptoms, they are not the primary cause of steering wheel shimmy. Low tire pressure might cause a different type of handling issue, such as excessive tire wear or poor traction. Worn ball joints can affect the vehicle's suspension and steering responsiveness but generally cause more of a clunking noise or looseness in the steering, rather than a shimmy. Poor alignment often leads to uneven tire wear and can cause the vehicle to pull to one side, as well as a feeling of instability, but is less frequently associated directly with a shimmy compared to wheel imbalance.