Repair advice needed for steering column adjustment.

First, here are the facts as I understand them.

My shop helper/apprentice has a 2nd gen base model Taco. He called this AM and says that his steering column adjustment will not lock in place. Basically as he described, it tilts and telescopes as it should but wont stay put once he gets it into desired position. He did say that he had unlocked it to make an adjustment immediately before this happened. All I can find in searching is stuff about vibrating steering columns and rubber stuff wearing out, so here I am!

He has a bit of a commute and no alternate vehicle, so I told him he could take the day off or whatever and not to put himself or others at risk. He is good mechanically and he's trying to fix it as we speak. I do all my own work on my first gen, and would like to help him if I can. Any advice? Thanks in advance.