I’m going to offer some solid facts, and also some opinions on the type of lubricants, where there is some controversy.
1. What to lubricate?
On rolling stock: (not locomotives)
- the most important part is the journals, where the ends of the axles turn in the “bearings” of the sideframes.
- Not quite as important, the areas where the truck swivels on the chassis bottom
- Couplers might need lubrication where they pivot on the body or in the “draft gear”
- Basically anything that moves in the gear train
- Bearings and bushings
- Where the motor block swivels in the chassis
2. How often to lubricate?
That is a tough one.
Clearly squeaking is time to lubricate, but that is a bit late. Look for dry areas, if using grease, look to see if it is still there and not hardened and on the surface, if using oil you should be able to see a film.
If the area is really black or gritty, then clean it out and re-lubricate.
“Sealed” gearboxes should be inspected less often, but check it at least yearly, and more often if you run a lot. Be sure to at least inspect it when you first obtain the locomotive.
3. Getting to the lubrication points.
This can be fun!
For rolling stock a needle oiler for the axle journals works, if using powdered lube, then usually the tube has a small hole and you kind of squirt it in there.
For gears, you want to get it on the gear teeth. This normally means opening the motor block.
Look online of how to open the motor block. Google something like “USA Trains F3 gearbox” for example.
4. How much to lubricate?
SPARINGLY is the watchword. Most people over-lubricate and the oil or grease can run everywhere. Too much lubricant attracts more dirt and grit, this is like sandpaper in your bearings. Over-lubrication can cause electrical issues, like motor commutator / brushes. Also be careful of any other power pickup brushes, do not get oil or grease in them.
5. What type of lubrication?
First, don’t cheap out, get plastic compatible lubricants. You use so little, trying to find a cheap alternative that is not specific for model trains is just plain foolish.
There are a number of brands of plastic-compatible oils and greases.
Oils come in thickness ranges from light to heavy. The heavy oil is nice and tacky and stays put. Lighter oils for the siderod mechanisms on steamers.
Medium oil—sparingly on motor shafts
Greases on gear teeth. I do not favor Teflon grease, as it does not “work into” the surfaces like greases with graphite or better yet moly in them. I do use dry powder when it is metal in plastic, like most rolling stock journals.