Bought a used tractor with only 120 hours. However, after about 5 to 10 minutes of running tractor (after it warms up?) it starts grinding when it goes into gear. When this happens, when I push in the clutch it makes a chatter like it's making something spin and will grind if I try to put it in gear. Dealer said tractor sat for a while. Could clutch be bad on such a low hour tractor? Thanks..