For what it's worth...I have over 530 games in on mine now. Just looked at them up close last tuesday. And they still look like at just put them in...

I have had my Funhouse for several years now, and I have about 500 plays. So far the gear has not broke, but I also make sure the gears are properly adjusted. To answer your original question the plastic gears are fine, especially the ones made of delrin. I believe it's a harder plastic.

There is a seller on Ebay selling metal gears, but it's very expensive and probably overkill for home use.

Good Luck.