New to the forum but didn’t see this particular question. I have a “newer” Lionel steam locomotive (number 561). Set it up for the kids, was working well for a while, then it stopped going forward - you can hear engine going and lights on, but wheels aren’t turning. I took all trains from the track and it seems to work fine in reverse, and will go forward at low speed on straightaway, but as soon as I give it some juice and/or it hits a turn, you can hear the motor humming away but the train stops, almost as though the wheels were spinning (but they are not, outwardly).
What does this sound like to you? My kids were loading it up with a ton of train cars, and my thought/concern is that they somehow stripped some gears? Sound right? What do I do about it?
I am not familiar with the 561 but know it was a “starter set” and quite well received. It was not designed to handle a ton of freight cars and there were user alerts that doing so would result in motor damage. Users often indicated the single traction tire needed replacing to maintain forward traction. However, since you indicate the wheels don’t appear to be turning, the traction tire does not appear to be the culprit. In my Google searching, I have not located gear failure issues but, if the gears are plastic, they could be stripped. Have you separated the motor from the shell to take a peek?
I have attached a link that you might want to look at.