I recently obtained a Lionel #2037 locomotive and 6 cars from my 97 year old aunt (still living at home). I am not familiar with Lionel locomotives, but I watched several youtube videos to know what parts were missing. I replaced the 2 missing chest screws that held the front end in, and I purchased a missing "cup" that fit inside the smoke unit. This cup has a spring and a rod. The rod did fit inside the channel, and the cup with the spring fit inside the smoke unit. I am just guessing here, but when put together, I think the rod that sticks out the side is suppose to be moved back and forth when the wheels turn, creating the puffing of the smoke, but the rod just stays forward and does not move. It will move with your finger, but generally it just stays forward. Am I correct that this rod is suppose to move back and forth to make the smoke "puff"? The heating element seems to work as smoke does gather inside the smoke stack, but it is not pushed out. Would it help if the spring was stretched out a bit? Any help would be appreciated. Thanks.