Looking for On 30 gas mechanical disassembly instructions

[old pilot]

Hello All,

I just purchased a gas mechanical engine on Ebay. It has a slight hesitation on each rotation of the wheels. Before I try to take it apart to check the plastic gears for cracks, I would like to find some guidance/direction on how to properly take it apart.

Do these plastic gears crack with age as do some other manufacturers plastic gears?

I see the Bachmann parts store has a replacement set of gears (all 6 gears) to order if that is my problem.

Has anyone replaced these gears? If so, is it difficult, any special tools needed, etc.?

Is there any other area to check relative to this hesitation problem?

Thanks for any help.

Old Pilot

[Fred Klein]

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.

[old pilot]

Hello Fred,

Thanks for the info. I too like the little engine and want to see it run well on my switching layout.

I found several videos on replacing the gears, etc., so I thought I would start taking it apart to see what I could determine. However, after removing the body and one cover plate, I decided this was going to be beyond my old age fading eyesight and manual dexterity. Since I only live about 90 minutes from Phila., I will make a road trip to Bachmann in the near future and let their experts do the repairs. With my sometimes history, it will probably be cheaper in the long run. I'll post the results after the repairs are done.

Old Pilot

[Fred Klein]

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.