Lower drive belt something not right

[durkinnj]

I recorded a better video. You can hear it’s fine at first but then it starts this higher pitched whining sound.

 

[bertsmobile1]

The high pitched wirring sound is a dry bearing or perhaps a belt slipping on a flat idler pulley, hart to tell from the video
Usually a slipping belt will be accompanied by some smoke & a burning rubber smell.

 

[durkinnj]

I ordered all new bearings. Will replace all when they arrive.

 

[durkinnj]

UPDATE: Replaced all of the deck bearings and it runs much smoother now. Annoying loud sound and vibration is gone. Thank you all for your help with getting this mower going. Runs and cuts great for a cheap old tractor. Cheers.