I am a tech for a deere dealer in Il....we have had alot of probs with the f/h reversers this fall......the tech books say the top end speed should be 715 rpm....we think that is too fast,,,,we have been shiming them to 680 max....if this is not fast enough,,,,overdrive your corn head......seems when you speed the f/h up the belt is way to tight.....check this out.....could save you big bucks.........