Help! Lionel 6-18226 General Electric Dash-9 Demonstrator

I believe you do remove the cotter pins to gain access. I've attached the diagram for this locomotive, as I had a similar issue when I had one. Sounds like the armature isn't connecting with the worm gear inside the truck

Most likely the plastic worm wheel is stripped off the axle or has cracked. This is not uncommon, This problem is going to surface a lot as the engines are now 25+ years old and the plastic is aging and under a lot of torque.

Thanks a lot for that exploded diagram, very helpful!

That plastic gear sounds like a very likely culprit. I was pulling a heavy consist and it was a sudden failure. When I turn the wheels there is no grinding, no drag, like a piece of the drive line just disintegrated.

Looks like Brasseur has the part. How difficult is it to replace this?

I'll give an update once I actually get into the truck which won't be today.

Well, almost a year later and finally pulled this motor apart. Looks like the gear slipped off the knurled portion. I don't see any significant damage to the nylon gear and it fits firmly over the knurled area (need to pry into place with metal picks). It was completely off of the knurled portion. I plan to use some loktite on there, is this a good idea? I'm thinking epoxy is a bad idea incase the gear needs to be replaced in the future. I could at least break the loktit free at that point. If loktite is good, should I go blue or red?

Thanks again guys!

Loctite won't hold to Nylon for very long. I would replace it with a brass gear.

I agree with @Chuck Sartor, a new non-nylon gear is due. However, according to the parts listing, it should already be a bronze gear, 623-22, which is available from well stocked parts suppliers: https://www.lionelsupport.com/...amp;CFTOKEN=33055634