Using the same mower for a few years now and haven't changed the belt yet. It still cuts fine, but I'm starting to wonder if I'm running on borrowed time. Some say replace it every couple of seasons, others wait until something breaks. Not sure which approach makes more sense. If the belt looks okay but has small cracks, is that reason to replace it right away, or can it still last a while? Rather not deal with a sudden breakdown mid-mow, but also don't want to replace parts that still have life. Curious how others handle this. What do you actually check before deciding to swap it out?