Which of these can cause front wheel shimmy?

Front wheel shimmy can be influenced by several mechanical and structural issues within a vehicle's suspension and steering systems, and one of the most significant factors is a loose steering linkage. A loose steering linkage can lead to excessive play in the steering system, causing the front wheels to vibrate or shimmy as the vehicle is in motion. This vibration is often felt in the steering wheel and can affect overall vehicle control, making it crucial to ensure that the steering linkage is properly tightened and maintained.

While uneven tire pressure can lead to handling problems, the specific characteristic of shimmy is more directly associated with the linkage that connects the steering wheel to the wheels. Similarly, worn brake pads and faulty wheel bearings do have their own effects on vehicle performance, but they typically do not manifest as shimmy in the same way that a loose steering linkage does. Thus, addressing issues with the steering linkage is essential in preventing and correcting front wheel shimmy.