Commercial refrigeration unit evaporator fan is super loud

I feel silly making a board about this but wanted to know if this is a DIY fix before I call the pros. The unit is still cooling properly.

So the compressor kicks in
Evaporator fan starts spinning
Evaporator fan makes godawful noise until compressor clicks off.

I pulled the unit out and the whole inner motor of the fan seems to bob in and out (normal?)

Almost sounds like fan is hitting metal but I can’t figure out what it would even be hitting???

What recommended action do I take?

Sounds like the berrings on the fan are gone. See if you can find a replacement. If it’s a 50 dollar motor it might be in the realm of give it a shot. If it’s a 400 dollar motor you’ll probably want a professional opinion.

Sounds like the bearing is shot, maybe it’s come apart. You’ll probably need a new fan.

Does the evaporator fan turn off when the compressor stops? If it runs quietly when the compressor is off but noisy when on the only SWAG I could give is maybe some ice is forming and the fan blade is hitting it.

But if the evaporator fan shuts off with the compressors and is noisy when ever it runs then I would replace it.