Here is a mother quick check. Park on level ground, smooth concrete floor with slick cardboard or milk cartons under the front tires. Turn full left and right. Does the front end rise up in each direction? This is a caster check. It should rise but not a terrible lot. To much caster can cause it to return to quickly and possibly the opposite direction. By shifting the angle of the front axle, the spindles have to lift the truck each direction. The weight they lift is what causes the steering to return to center. You want enough caster for a smooth return, but not so much you have to lift the truck in each turn. This is most noticeable at slow speeds in sharp corners. You will also notice to little caster at highway speeds, the truck will be jittery and not want to follow a straight line, you will always be correcting it. Again, it's the weight on the spindles that holds them straight.
Picture the axle hanging by the spindles exactly level. If you turn the spindles, they move in a level arc, even with the center line of the axle . Now rotate the axle 45* clockwise, they still move in the same arc, but rise above and below the axle center line. You just added caster angle.
We can assume you have adjusted the steering box and greased it?
Joe
