I've replaced the discharge beater drive pulley and belt, as well as the blades on the discharge beater, running notched side out. I also replaced the discharge paddles on the rotor. I'm still running two paddles, but I'll be adding two when I replace the seperator bars. I'll also shim the solid helicals. Is there a measurement to tell me when to replace the seperator bars, or is it strictly a judgement callIJ The operator's manual says to replace them when they're worn; it just doesn't tell you how to judge when they're worn out. Thanks a million!