I did learn today that this tractor has some type of clutch inside the gear box. I'll be tearing into it tomorrow and I hope to find my problem.This tractor had set up several years before I got it. I changed out all fluids & filters soon after getting it running. I went to put out rye grass w/hopper seeder and found out the PTO wouldn't turn. I have pulled the inspection plate off by the shifter but don't see anything to be wrong.