Welcome to the forum!

Lionel has service literature for most of their products, and most of them have exploded view diagrams of parts. The 3619 does not have an exploded view diagram available, just a parts list and operating instructions. If you can post a few photos of your cars' mechanism from different angles, it may be possible to ascertain what parts, if any, you may be missing.

Larry

 

Your answer could be in the 3419 car

I don't have a 3619.

 

After I posted my question, I got busy with work and pushed this off to the side. I finally got around to starting on a layout last week and last night I got this car out and was determined to figure it out. The trip mechanism is just a wire that trips a lever as the arm raises up. It was still intact on my car but it was bent way off of how it was supposed to be. After a lot of testing and some oil on the gears, I finally got it to work. In the pic, the arrow is pointing to the wire and the straight line is pointing at the trip lever for the copter. The wire just hangs loose and even sticks out the bottom of the car a bit and has a hook bent on the bottom. The wire has to be in front of the trip lever when you lower the arm down. Getting the bend in the wire correct took the most time. When the arm raises, the trip lever pushes against the wire and with the bent angle of the wire, the arm continues to go up and eventually trips the mechanism. My wire had been bent in several different positions so it was hard to get perfectly straight and wanted to catch a little bit. I put a drop of oil down the wire to help it not catch the trip lever. Hopefully Im not making this to confusing. The link is a video of it in action.

https://www.youtube.com/watch?v=Ad9jevXt3CE&index=1&list=UUoRxisU22b9SUrg6TX9kJuw