broken

My Kato E5 N scale stopped working so I took it apart, when I took it apart I saw the this thing (sorry, don't know the name, in picture) wasn't working so where can I get a replacement part?

Okay, so volcano might be a stretch, but that's how it looks to me when my dear train is freaking out. It's from 1993, family got it when I was two. It was the family train and was used at Christmas and any time we kids wanted to play with it. When I went off to college, I didn't get to see...

I have a Lionel engine I received as a kid probably 30 years ago. It is a steam engine with a plastic body, the number 8602 silk-screened on the side--I don't see any other serial numbers or part numbers visible). I'll attach a photo in case that helps! (Please excuse my disorderly desk!)...