My 48" Snapper WB keeps shredding the belt from the engine to the transmission. I can only get about 1 month worth of work per belt. All other belts do very well. I have checked all pulleys for problems, but have found none. What I think is that since the belt is only 1/2" that the work load is too great? Am I right here. I have tried multiple brands of belts to no avail, they all shred within a month. Any suggestions?