Steering Wheel Return to Center
If something is binding in the column, linkage, or gearbox, the steering wheel return to the center will be affected. Steering wheel returnability is dependent on the caster angle, and most vehicles incorporate positive caster (~ 6-7 degrees) into both front wheels.
Turning the wheel lifts the front end a little, and releasing the wheel allows the weight of the vehicle to push back down, assisting return to center.
Binding front end parts cause steering problems. Check the ball joints, tie rod ends, idler arm, and other linkages for binding. Be careful when installing these parts, many vehicles require the wheels to be straight on the final torque, or the part will act as a spring returning it to the turned position.