Thanks for all the great replies!
I have an L298N motor driver, but after it's worn out even connecting it directly to a power supply it won't run. The motor seems to have a lot of lubrication on it already and it starts to become weak and slow and eventually quits.
I have dissected the gearbox and it doesn't look like a mechanical issue because the gears still turn freely.
The same motor I have used on applications where it isn't dragging along with a chain & sprocket and I've been able to run it for the 10-12 hours a day for up about a month now.
@Railroader now I'm wondering if running it intermittently (a few minutes on, a minute off) would help or if eventually I'll be back in the same place? I will be looking at some heavier duty stuff for sure. I started looking at stepper motors but maybe a heavy duty DC is more worth it?