The belt that broke today had about 6 hours on it. No wear showing anywhere. I talked to a mechanic at JD and he said to check the washers and sleeves for wear under the tension bar. They looked okay. I checked the spindles and noticed that the left spindle only spins about half as long as the right spindle with similar torque. It's not harder to start spinning but is not nearly as free as the right spindle. Could this cause the problem? Any suggestions? It's an x300 with 80 hours on it. Thanks.