Steering: Steady Pull
A steady pull is present at all times. This is different from bump steer (caused by a bump in the road) or memory steer (caused by a binding steering component) after a turn. It’s a constant pull to one side and can be caused by a variety of situations, depending on the vehicle and type of steering/suspension. Most causes are general and apply to all vehicles. These include the steering angles caster and camber.
Caster: The caster angle is measured in degrees. It’s formed by a true vertical line and a line through the center of the vehicle’s strut. It's the forward and backward tilt of the steering axis as seen from the side of the vehicle. If caster is not equal on both sides of the vehicle, it will pull to the side with the least amount or most negative caster. Manufacturers use this adjustment to compensate for crowned roads. An out of specification caster angle is typically due to a broken or bent part, possibly caused by a collision. Most vehicles have positive caster. Positive caster helps with stability and steering wheel return.
Camber: The camber angle is the tilt of the tire inwards or outwards from the tires true vertical center line as viewed from the front of the vehicle. The vehicle will pull to the side with the most amount or positive camber. The camber angle is a tire wearing angle. In the illustration you can see how this angle can wear the tire on one side or the other, depending on whether it's angle is negative or positive. This is different from caster which is not a tire wear angle.