Can't hear it with my ear muffs on but I had them off for a little while yesterday to listen for issues while mowing and I realized the 60" 420 deck is getting louder. Sounds like the spindle bearings are almost worn out. Probably need to replace them. It spins freely though. No unusual noises turning it by hand. Just a howl when it's running. The left side spindle gets warm too. Haven't checked the other ones but it doesn't really matter. If I have to do one I'll do them all.