Well, yesterday I tried to engage the blades on my B7510 after not using the Midmount mower all winter. When I tried to engage the blades, the motor bogged down until I pushed the clutch in. I tried again and again. Still nothing. Finally I took the shrouds off and pulled on the belt. After rocking the belt back and fourth.....I was able to get back on the tractor and engaged the blades. It was really loud. I thought it was rubbing on the metal so I turned it off and greased all the spindles and the shaft. It was still loud for a bit. It is somewhat quieter now, but no where near as quiet as before. The tractor only has 36 hrs on it. Only about 10 hours on the mower. Any ideas?