I have an old Toro S 620 that has served me well, and decided it was time to tune it up and get it ready for the upcoming season. I replaced the paddles and scraper bar and have come up with a problem. The new paddles hit the scraper bar when it rotates. Is this normal? It starts and runs and still spins the auger but it makes a lot of noise every time a paddle hits the scraper. Am I supposed to remove some material from them or will they wear down quickly or did I get the wrong part? Thanks for any help.