If your vehicle is showing uneven tire wear on the inside or outside edges, here are the most likely causes and the parts you'll need to fix each one.
Normal driving over bumps and potholes gradually knocks the wheels out of alignment. This causes the tires to drag or lean excessively, wearing down the inside or outside edges prematurely.
Replacing steering or suspension parts without performing a wheel alignment immediately afterward guarantees the wheels will be out of specification, rapidly destroying the tire edges.
Tie rods connect the steering rack to the wheels. When they wear out and develop play, the wheels can point slightly inward or outward while driving, scrubbing the tire edges against the pavement.
Ball joints act as pivot points for the wheels. Worn joints allow the wheel to tilt inward or outward at the top, changing the camber angle and putting excessive weight on one edge of the tire.
Rubber bushings cushion the suspension. When they tear or degrade, the control arm shifts under braking or acceleration, dynamically changing the alignment while driving and causing edge wear.
Worn struts or sagging springs alter the vehicle's ride height. A lower ride height directly changes the suspension geometry (camber angle), leading to inside edge tire wear.
A loose or failing wheel bearing allows the entire wheel hub to wobble. This causes uneven tire contact and edge wear, usually accompanied by a noticeable humming or roaring noise at speed.