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

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?

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

First of all, thanks all for your input. I'm new to this so all help is appreciated. I re-soldered the wiring that I broke ... a pretty sloppy job but the connections are good. I cleaned the tracks, the contacts, bent the contacts in, and added a little weight with tire balancing weights. I was having fairly good results. I am just testing the train so it is on an ez track oval sitting on a flat carpeted surface. I may have intermittent continuity because of that or it may be the cheap black ez standard track. Whenever I get to the final set up. I'll be using the nickel track with gray roadbed.

I did also post a question about the worm gears of a HO Jupiter. I have some of those that I want to convert to Civil War USMRR pieces. I have 2 that the worm gears have come loose. Is this a repairable problem or a a final epitaph?

Thanks as always,

Rick

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?

Thank you all for your help. I've tried  everything you suggested and it helped. It does not require as much downward pressure on the back of the tender to get it running. I did order some adhesive lead weights to attach to see if it will help. In the meantime, I need to solder back the wires I pulled loose while fiddling with it 
Thanks again,
I appreciate it,
Rick

Thanks for the tip Jonathan. It was actually only about 15 minutes run time out of the box before the second try. I'll do as you suggest.

I just purchased a new, never used / old stock Bachmann 4-4-0 Confederate train set. When I first tested it before setting it up, it worked. After I set it up, it ran fine. About 8 hours later, when I turned it on again, the light came on but it would not run. After playing around with it, I found that if I push down on the back of the tender, everything works, forward and reverse. As soon as I take off pressure, the wheels stop turning but the light stays on. Has anyone encountered this problem or have any idea what is wrong? I would appreciate any help.