Jupiter 4-4-0 old

[wrg]

I'm just getting into trains again and I've been tinkering around with some old Jupiter 4-4-0s just to see how they work and come apart. The worm gear came out and doesn't seem to want to stay in place now. I thought maybe it was broke but I can't see a broken shaft or anything. What am I missing? Before I started to "work on it" the wheels would turn as long as I was turning the drive shaft. They would not turn freely by themselves. Can you replace the worm gears in these older models?

[Terry Toenges]

I assume you have reconnected the wire from the tender to the back of the boiler with the screw that also keeps the worm gear housing in place? The pic they have online is different than the one I have. On mine, the plate holding the drivers in place is separate from the piece for the wire that also holds the worm gear in. I don't know which one you have.
https://www.bachmanntrains.com/home-usa/dwg/dwgs/4-4-0.2.pdf

[Terry Toenges]

This is mine.
The small hole above where the drive shaft fits in is where the wire is screwed in.

You can see the separate worm gear housing out of the loco.

[rich1998]

I'm just getting into trains again and I've been tinkering around with some old Jupiter 4-4-0s just to see how they work and come apart. The worm gear came out and doesn't seem to want to stay in place now. I thought maybe it was broke but I can't see a broken shaft or anything. What am I missing? Before I started to "work on it" the wheels would turn as long as I was turning the drive shaft. They would not turn freely by themselves. Can you replace the worm gears in these older models?

With the interaction between the worm  and the worn gear on the driver, you cannot move the drivers easily without stripping the plastic worm gear on the driver axle if I read your message correctly. ou will have to jiggle the worm to get it back in.
Look at the parts page for the loco and you will see the worm gear on the driver axle that mates with worm driven by the plastic shaft from the motor.
I have two of these locos for some years.

Edit.  I know Bachmann calls it a worm gear but NWSL calls them a worm and they drive a worm gear. If the mesh is too tight, they will not turn.

Rich

[Terry Toenges]

In my loco above, without the worm gear carrier screwed down, I could turn the drivers and it would push the worm out. I can remove the whole carrier that way without unscrewing the plate from the drivers.
Here's a video.
https://youtu.be/Mcrx5ZUB5C8

[wrg]

My worm gear doesn't have a housing. I have just a gear and a plate. My locomotives are red and silver. I assume the plate is the only thing keeping the gear in place? I think I might have it put back in place but I have to re-solder the wire connector that goes from the tender to the locomotive before I can test.

Thanks as always, Terry and Rich for your wisdom.

Rick

[rich1998]

Here is a diagram. The plate keeps the worm in place.

https://www.bachmanntrains.com/home-usa/dwg/dwgs/4-4-0.2.pdf

I took a couple of mine apart many years ago for a dab of 102 Labelle gear oil.
My 108 had a fine point for motor bearings and axles.

Rich

[wrg]

In the diagram it looks like the plate is part of the chassis underframe. In my trains the plate is a stand alone part and is not part of the underframe. I guess I'm looking at it correctly?

[rich1998]

Bachmann seems to vary in design.

Rich

[Terry Toenges]

Rick - Now I know. I was going to offer to send you one off my old parts loco but I guess it's not what you need.

[wrg]

Thanks Terry and Rich. Thanks to all for the help I have received. I actually now have 3 trains that are in running condition. Rick

[rich1998]

Don't forget Hminky tuneup ideas. They helped me some years ago to make a better running Bachmann tender drive loco. I pulled the motors and put in oval can motors with the same size drive shaft. About the length of the tender. Not quite oval. I guess you would say four sided. Out of old CD drives.

Rich