If you are going to attempt steering box adjustment DO NOT adjust the box with the wheels going straight ahead! If it is determined the box needs adjustment turn the wheels full lock (either side) and make your adjustment. If you find it's still too loose the box needs a rebuild.
Why? Most wear on any steering box is at 1/4 turn from either side of center. If you adjust the box here it will be far too tight once you turn the wheel farther. Galling, binding, and even breakage can occur on overtightened steering boxes.
Adjusting the box is not hard just be patient. Look over everything in the front end. It could be anything from a loose tie rod or ball joint, don't forget to check the mounting bolts for the steering box itself. Good luck! Let us know how it goes.