Getting the Spur into the SX3

[corsair]

Hi folks,

I'm building this car right now, and I've one burning question...might sound stupid to most of you.

In step 3b, how do you get the Spur gear with the shaft to fit in the transmission holder, without somehow forcing the spur to sit into the notch?

I've to use some force to get it in and I noticed the sides of a few teeth are slightly ruined. The spur as of now is still fine to use, but should I need to change spur gear, wouldn't this be a hassle?

Some enlightenment would be great.