The engine makes a mechanical raddling sound, particularly when going around curves. It sounds like the motor gear box needs lube or something. I don't mind taking it apart, if someone can tell me what it needs. Thanks for any advice.
Dual engine motors make lots of sound!.
Observe the engine on the curve without the shell . Are the motors dancing? The fields are held on with rivets they could be loose. The lower truck could use grease around the gear in the center axle. Check that for wear. If it appears to be worn check the axle play for a worn bearing. The important thing is does it run ok? aside from the noise.
Then the light oil also appplies to the armature.
I ran it with the cover off after greasing the gears and oiling the armature bearings. Everything seems "tight", nothing obviously loose or sloppy. I did see slight arcing from the field rivets. What is the best way to tighten these?
I am not a fan for rivets and replaced mine with # 6 screws on my 2333 motors. You can try to tighten by hammering but it may be worn to the point it will get slack. THe arcing is interesting. One of my engines juggled because it was so loose the armature couldn't spin. I also had a thrust bearing missing so the armature didnot spin within th field. It was in sad shape. Plus my center brass drive worm gear was worn along with an axle bushing.