Keep the wind and the road conditions in mind.

Test the vehicle, going in both directions, on a flat road.

The wheel alignment settings are incorrect.

Adjust to specifications. Refer to Wheel Alignment Specifications in Wheel Alignment.

The steering gear valve is unbalanced (if this is the cause, steering effort will be very light in the direction of lead and heavy in the opposite direction).

Replace the gear valve. Refer to Valve Replacement in Power Steering System.

The steering shaft is rubbing the inside diameter of the shaft tube.

1. Align the steering column.
2. Replace the steering column as needed.

Refer to the following procedures in Steering Wheel and Column:

The tire inflation pressure is low.

Inflate the tires to the recommended pressure. Refer to Tire Inflation Description in Tires and Wheels.

The front or the rear brakes are dragging.

Adjust the brakes.

The front spring is broken or sagging.

Replace the spring.

The front wheel alignment setting (camber) is incorrect.

1. Check the camber setting.
2. Align the suspension as needed.

Refer to Wheel Alignment Specifications in Wheel Alignment.