I have a land's pride bush hog that's about 6 years old. I only use it 3-4 times a year. Today I went to my property in Alabama to check things out and take the Kubota for a spin. But, when I pushed the clutch in and moved the gear to disengage the bush hog, it didn't stop rotating. I tried 4 or 5 times with the same result. Finally when I turned the tractor off the bush hog stopped rotating but made a loud bang when it was almost done. Did I screw a gear up or could lubricating solve it?