First, easiest check is steering fluid level; if it's low that may have a lot to do with steering being unresponsive and will often be heralded by a buzz when turning the wheel. Do any hoses or the steering box show signs of leaking? Maybe the message isn't getting to the wheels.
Have a friend help gently shake out the steering for loose parts like tie rod ends or kingpin bushings. One of you rocking the steering wheel back and forth while the other one watchs for loose joints in the steering linkage from box to wheels (this often works better with the front wheels on the ground so as to make any looseness more pronounced than if the wheels are in the air and allowed to steer freely). *As long as you're under there; it's a good time to hit any and all grease fittings with a grease gun.
If there is play but all the joints are tight then check the box; is it tightly bolted on? If the box is working loose, tightening it up will help a bunch and will also stop the bolts from wallowing out the mounting holes. If everything looks solid then watch the pitman arm; does it move as soon as the steering wheel is moved? If the play is there, go take a look at the CUCV manuals in the Tech Library section for the 20P covering steering adjustments.