1964 JD1010U CLUTCH issues

Hi there I am looking for any information on why my Tractor clutch will NOT disengage? I have to turn it off to switch gears. It runs and drives great but I want to fix this and I don't even know where to start. I just replaced the radiator(previous owner let it freeze) and the water pump...Any Ideas?? Whole clutch system?
And from a previous Post I asked about the 1010u, I looked in the book that I have and it says that they are the 1010RU but have the ability to run a Mower (assuming as well as brush hog)? Made for the Highway dept and parks Dept. I cannot find ANYTHING else on them and I found a really beat up one(that was yellow) on a link to a former ebay posting...Mine is traditional JD green and has all the decals.
Any help is appreciated!

See my post to your other thread about the clutch. My 1010 is a Utility too. Things are a bit different with them, particularly with the steering. Does yours have power steering with the cylinders going to each front wheel?