Ticking noise

[HIHUMMER]

Ok..in my girly terms b/c I'm still learning:

The red arrow thingy (ring?) has the teeth chipped and the base of the teeth have hairline cracks. Now, the blue little thingy (pinion?) has scratches and scars on each tooth and 1 of them actually was broken in half. They are replacing both pieces. Actually would have been fixed today, but someone dropped the new "ring" and broke off 2 teeth.

Now...on the outside of the whole casing that holds all these gears, on top there was something that turns. a yoke maybe??? well, he put this gauge on top of it and told me that the needle should move between 10-20 degrees when he rotates it. So he moves it and it doesn't even get to 5 degrees. What is that all about?

Is any of this making sense to anyone? I'm so sorry..I just don't know what's everything is...yet?!