I had a 04' 9660 and the shoe frame that held the shieve and chaffer gave up at 600hrs. Had cracks around the main support bolts on the left side.Deere replaced the shaker frame and all rocker arms and bolts. The replacement frame was made out of thicker steel. I traded for a 07' 9660 with bullet rotor. A rocker arm broke on it at 300hrs. Deere replaced the two front large arms. Then the water pump went out at 600hrs. I traded for a 09' 7120.