I seem to have the same issue...the blade slips off all the time. I tried putting it back on, but there are no rubber bands around any of the wheels...on the parts diagram website it doesn't list any rubber bands, only a timing belt....the belt on mine seems fine, it just seems the blade falls off the wheels due to the way the wheel is designed....IF it is just rubber bands, can standard rubber bands work for a quick fix or do you have to order the one's from the dealer?