I recently replace the pto shaft in my TO20. Since, I never really had a reason to use the tractor I don't recall moving it, but I'm certain that I checked to make sure the tractor could be placed in gear. I know the PTO worked fine. Well yesterday, I tried to drive the tractor, but It would not go into forward gear and occassionly in reverse. When trying to place the tractor in gear, I could grind the gears. I could also place the PTO in gear while the tractor was running. When tractor is off I could put the tractor in Forward and reverse with ease. At time I did not consider the clutch but someone suggested that I adjust the clutch/ How is this done?