Can you clarify a little - was it working, and stopped working? Is it stuck in one position, or freely moving without locking in place?
The reason I ask is I have a 1999 TC-2000 FE - not sure if mine has the same steering assembly as yours, but evidently my bus must have had the same driver forever - and that driver liked the steering all the way forward. Mine had sat in that position for so long that it either rusted or gunked up with crud into that position. I tried brute force over and over again and finally shot some WD-40 up into the mechanisms and kept yanking it until I felt it start to break free. For a week, I made it a point to move it back and forth a couple times a day at least. Now it's as smooth and easy as can be and the lock works like a champ.