Hi Chris

Welcome to the collective

It sounds like you stripped some gears. I have done this before... It does require a tear down to replace. You might be lucky and it is just the intermediate gear, which is easier to replace. What I did was replace the spindle gear with a
METAL one and left the intermediate as plastic. Having a plastic gear is sorta like having an extra safety. Better a gear strip than something else break. The metal spindle gear guarantees it will be the intermediate gear that breaks.
Since you will be doing this, maybe you might want to consider replacing the bearings with tapered bearings...
Instructions on how to do this
HERE. You can also see what you need to do to replace the gears...
I have been there, so if you need any questions answered, feel free to ask. Good luck!
Eric