Tomy holiday set parts needed

[Super]

You could try to glue the gear but it may still slip since the crack will be a bit farther apart. Best that you replace it. Gears can be easily found cheaply on Amazon or Ebay.

I guess the Helicopter building is prone to being noisy. I don't have any experience with one myself but the one on Muddy Poppins Layout seems to always be noisy in all his videos when a train passes by.