I am new to this forum working on an interest in Brass trains and an HO layout. I recently purchased two Brass GP 20 engines on eBay, one in PRR and one in New York Central. The PRR operated for about 10 seconds then stopped. The motor still runs but the wheels do not turn. I attempted to take the top off but have not figured out how. I removed two screws on the bottom but no others are visible that affect it. I would like some advice before I destroy the engine? I am located in Bellefonte, PA 16823 and have considered modeling the Bellefonte Central in one of its time frames. I have purchased some brass trains majoring on the low end price wise. The diesels so far have been lower priced than the steam.
I also have one of the Tenshodo GP20s. The shell is held on by two screws under the cab (which I assume are the ones you removed), and two more screws near the back of the long hood above the walkway. They blend in surprisingly well when painted, but they're pretty obvious once you spot them.
After the shell's off, there will be two or three light bulbs clipped in the front and back. Those should just pop out. The rest is very easy.
The universal is mounted with set screws. It's likely one of the joints has come loose. All it needs is a little tightening with a small flat head screwdriver. While you're at it, it would be a very good idea to completely clean and relubricate the entire engine. These things are a minimum of 45 years old, and grease and oil can get very stiff with age. After all that's done, it'll outlast anything else you've got.
I repainted and remotored mine with a flywheel, and added much better Smokey Valley handrails and constant directional lighting. Sure, it doesn't nearly measure up to a Proto 2000 GP20 in looks or gear noise, but it is one heavy puller!
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Welcome to the forums.
Do you have any pics of the loco's?
Springfield PA