There is 611 hours on the tractor and the clutch was changed @ 591 hours. Now there is a rumbling noise when the gear lever is in 4 th @ 8 th gear. The tractor does not have to be moving. It gets worse when you are driving it. The dealer that installed the clutch does not know if they can find the problem. It started when they installed the clutch. The noise stops when the foot clutch peddle is pushed down. I need help! Larry