Dusten, I would be very surprised if you find all three of the cars you want for less than $100, considering that the retail price in the Bachmann catalog for each one, at the time was, if I remember correctly, in the neighborhood of $70.00 to $90.00. I found mine at train shows, used and missing parts, for about $45.00 each. Notice I said train shows (plural). It took a lot of searching to find the cars. Best of luck.

Thanks for detailed feedback - something to keep in mind. Thanks again, Fred.

Hello Old Pilot,

After hearing your success story, I may just send in my engine. I would much rather have it running than just sitting on the layout. Thanks again for the update.
Fred

Old Pilot, sorry to hear about engine #2. After having done some exploratory surgery on mine, I totally understand your frustration. Looking forward to, hopefully, positive news in the future. Thanks for keeping us in the loop. And the saga continues....

Old Pilot, that is great news! Glad to hear that engine No 1 is up and running. Keep us in the loop, Fred

Old Pilot, I'm glad you came across those videos and for sharing that information. I wish you the best of luck in your self-education and subsequent repairs. Please keep us apprised of your progress as I am really interested as to your success. Thanks again, Fred.

Hello Old Pilot,

I ran into all of the same issues except I hadn't contacted Bachmann repair. For the moment all of my efforts are on hold and my GM sits on my layout looking pretty. Best of luck!
Fred

Hello Old Pilot,

As far as disassembly, that's about as far as I got as well. I'm 78, and at my age I just don't have the manual dexterity, nor the patience, to really get into the "guts" of the little engine. Like you, I fell in love with the little engine when it was first announced but, unfortunately, budget and life didn't make a purchase possible at that time. Looking forward to hearing about your "Repair Journey". Best of luck.

Fred

One thought: In your search for gears, you may want to check out North West Short Line (NWSL). They supposedly carry gear made of a different material. However, their website info is very obtuse. 

Hello, Old Pilot. I have owned one of the On30 Gas Mechanicals now for at least 5 years. When I first received it, it ran very well out of the box. Then life intervened and the little loco had to sit on the layout for probably 4-5 months before I had a chance to run it again. Now, the "little engine that could" couldn't. It just sort of loped around , stopping here or jumping rail there. Closer examination showed that one of the gears on the main drive train was split. I ordered a replacement drive mechanism (drive wheels, axles, connecting rods and wheel hubs) and installed it per the included instructions. Ran fine for a couple of weeks (if that long). Same problem. Rinse and repeat above. After replacing the drive train three times, I gave up and now have a "park monument" sitting on the layout. BTW, the "instructions" that came with the part were just about useless. Hope this helps.

Fred

I don't mean this to say that I'm "soured" on the little GM. As a matter of fact I'm looking forward to seeing the GM Mark 2 once it goes to dealers. I still would love to own one that works, so depending on my budget and price, it may possibly be in my future.

I, too, would be interested in more info on the new Davenport. I have an original one, but after having replaced the drive train three times due to split gears, I've given up and it looks real pretty sitting in the yard.

BB1, if your PCB has jumpers as shown in the picture, then you have the 8-pin jack. BTW, I have a 1995 vintage HO Doodlebug and it has the 8-pin jack, FWIW.  If not, the wires are usually connected to the edge of the PCB via little clips. In that case, you will have to solder. As long as there are at least 7 wires connected to the PCB the motor should be electrically isolated. Best of luck. Fred

BB1, if you go to the Bachmann Parts/Support section, in the N scale section and look under Gas Mechanical, you will find a document for the the Doodlebug called the Locomotive Chassis or something similar. On that drawing in the lower left corner you will see that that PCB (Printed Circuit Board) contains an 8-pin jack that is currently jumpered for DC operation. Remove the jumpers (perhaps take a picture for future reference) and insert the plug from the Digitrax decoder and you should be all set. If you go to Digitrax's website and use their decoder selector, they will show you which decoders will fit your application.

Here's a link to the document:
https://shop.bachmanntrains.com/documents/N_Doodlebug.chassis.pdf

Hope this helps.

Thank you very much Old Pilot, for the information. I will keep my eyes open on Ebay.

Thank you, Old Pilot for the details. Sounds to me as relatively straight-forward scratchbuild/kitbash project. Again, judging by the pictures, the cars look GREAT! One question: Where did you find the O scale canons? Thanks again,

Great job, Old Pilot. The pictures look very realistic. If you feel like it, please post a short note on your construction techniques. It doesn't have to be too detailed, just kind of a 10-foot overview. I, for one would be very interested. Thanks for sharing the pictures.