Start with the motor. If it turns, you're in good shape. Then, the worm gears, they are made of brass, they are pretty stirdy. You can clean them with steal wool is you like, keep the steel wool away from the motor. The frames are also pretty tough, They don't need to be perfect, you won't see them. just go over them lightly with the steel wool os S.O.S. The trucks have plastis gears, they shoul not have any corosion. Just clean them with dish soap and water with an old tooth brush.

Cleaning N scale locomotive. Kato SD40-2 CSX. I don't have Kato locomotives. Just Atlas, Bachmann, Life Like and Lima 🇮🇹. GP35 Southern Pacific is Dummy. My locomotives worked good.

When are you going to get an ultrasonic cleaner? No more tap water and toothbrush. I use mine, (from Harbor Freight) to clean everything, frame, body shell, trucks, (without having to disassemble them, and the wheels and gears come out spotless). I even clean the motor. It cleans the commutator, brushes, and bearings. As soon as it comes out of the cleaner, I completely hose it down with CRC brand contact cleaner, lubricate the bearings, and we're good to go. I've NEVER had any motor problems after doing that, and they run like new. It only takes 5 minutes to do a complete cleaning of the entire locomotive. I have some locomotives that I bought in 1969-1970, and since cleaning them this way they all run like I just bought them.

Great video. I have a question. I bought a Dash 9 from Ebay that had a lot of moisture damage from setting in a basement. Worm gear had rust build up. Frames had rust build up. Light board too. Motor had rust too. It's not major bad rust but its rust nonetheless. I cleaned it but still has a grinding sound and it still doesn't get good power pick up. Will these steps you do remedy this problem?