Toro Super Why Does My Toro Super Recycler Make A High Pitch Squealing Noise When I Engage The Mower Blade?

Why does my Toro Super Recycler make a high pitch squealing noise when I engage the mower blade? - toro super

I had access to my Toro Super Recycler mowers today after passing through a thick pile of weed, began a high pitched sound, metal on metal are makeing, howling before they turn on and off. When you restart do the same. Only the sound when the blade is engaged. I inspected the blade and seems to touch something, but if I move the blade with my own hands, it seems a little, to screech that. no idea what is wrong, and above all how to solve this problem?