Performax Belt Drive Motor Question

[John Weber]

A couple weeks ago the little variable speed DC belt drive motor on my Performax 16-32+ started to make a "different" sound. Louder and not the nice quite hum it had made in the past. It seems to work fine, but the wine is now rather annoying. I called Jet/Performax and they said not to worry, those motors are bullet proof. From my industry days, we replaced little DC drives all the time. So any ideas? Run it and don't worry, or could the sound mean something is up?

Thanks - John