[wilkin250r]

I would disagree with Longhair on his definitions of bumpsteer and rollsteer, but I'm not here to argue technicalities. Bump steer can be loosely defined as unintentional steering motion of the tires as the suspension travels up and down.

Because the front of the spring attaches at a fixed point, and the rear attaches at a shackle that will pivot, the wheels don't travel perfectly up and down. As the tires move up, the spring flattens and pivots the shackle away from the wheel, and the wheel actually travels in an arc upwards and slightly backwards.

Stock GM steering can work well in preventing bumpsteer just because the steering linkage is pretty well located for vertical travel and moves in the correct arc to keep the steering wheel and the tires in sync. Crossover steering will have some bumpsteer because the leaf spring suspension moves straight up and down while the crossover draglink moves side to side. Since the draglink end at the axle will move in an arc, it will have some small component of side to side motion as it travels vertically and this side to side motion causes bumpsteer.