Both manual and power steering boxes have an adjustment screw (with a locknut) that controls steering tightness. It is used to compensate for wear in the steering gear. The proper setting can be made or tested with the steering at full lock (left or right). The screw is made barely finger tight. All the wear is concentrated in the straight-ahead position, so it is way too easy to over-tighten the adjustment, causing the steering to bind anywhere but centered, or worse yet, break something irreparably.