Wow, this sure caught my attention. I have that same steering on my YM2002D. Often wondered what would happen if something went wrong with it because I have never seen a parts breakdown or parts listed for the unit. Often wondered if I would have to try and find a manual steering unit for it. My parts manual shows both a manual unit and a power unit but no breakdown of the inner parts. The lower gearbox housing actually looks like the manual gearbox but then has an upper cap assembly containing the power parts. I'm not sure the upper column couldn't be replaced with a manual column. Just rattling here but am going to try and post pictures of both for you. I googled the part number for a complete "manual" assembly and got a hit of a rebuilt one for about $550. Only shows it to fit through the 2010. Again, just rattling. if it were me, I would tear into it and see just what could be done. Any pictures of your progress would be appreciated.