Boat steering gear box?

I have an older bass boat it has an 85 hp jonson javelin motor. I tried to take it out last weekend but the steering was locked up. It will turn one way but not the other and when turning the wheel it gets to point where the wheel will go slack with about 90 degrees of play without moving the motor. There is an aluminum box (I assume is a gear box) beneath the dash that the steering wheel shaft goes down into. I assume it needs a new gear box, but I don't know a whole lot about boats. I can fix just about anything if I know what needs to be replaced. I looked up, boat gear box, steering box, steering assembly but cant seem to find anything related to my problem online or anything that looks like the part I need. Please help.