Yanmar 1510D Steering box trouble

New here, so please direct me if this is in the wrong spot. My (maybe) 30 year old dull Red Yanmar 1510D seems almost indestructible, especially with how I beat it up with added front loader and bushhog.
My steering made a ominous clicking sound when I turned right--it sounded like a broken piece of spring wire clicking against a metal part--but the tractor still turned without much play in the steering wheel. That was then. Now the clicking noise has stopped and there is about a half turn or more in the steering wheel when I try to turn either direction. I've noticed that when the steering wheel seems to be free-wheeling, that first grease joint next to the steering box does not move at all. When I turn the steering wheel to the end of the free-play, all the steering rods jump into action to turn the front wheels.
I'm pretty handy but dont have a hydraulic press, so I'm wondering if I should spring for a rebuilt steering column and box or is this something I can rebuild on my own. I'm not opposed to buying a new tool if it will save me the $400.
Any and all advise on this topic, including cautions getting in there, will be greatly appreciated.
Thank you, Ralph Shaffer