yup, take off a gaurd and look the the cutting profile, is it smooth and dipped in the middleIJ If so replace, if it is smooth and not dipped use a side grinder to put on a new cutting edge. How are your wear platesIJ Can you grab the sickle and move it forward and backwardIJ If so readjust the wear plates or replace and readjust. look at the back of the sickle does it have wear groovesIJ If so move the holddown and wear stips to another non worn area. I have installed wear plates in all possible holes. You need to have hold downs every foot. Verticle clearance should be no more than the box top thickness you sections came in. The material wedging between sections and gaurds is what is causing your breakage.