Went out of mow leaves on my 52" Mini Super and the clutch seems to locked up. the mower is about 5 years old with under 150 hours. Ran and mowed fine two weeks ago. When I get down under it and pull the pto switch I can hear it click like the clutch is try to lock or unlock. Can not turn the belts so the clutch is locked up. Anything else to check or off for a new clutch?