Update Gentlemen, On this Lionel Model, accessing the worm gear requires removing the cover, crew seating, antenna, wiring harness and dropping the motor-truck off the body. Then you remove the truck detail on the drive gear side and you can reach an opening to the worm gear. You could obviously remove the motor from the truck at this point, however that also requires more numerous steps.
I could see the worm gear opening through the top of the truck detail bracket. After some creative thinking I took a grease gun removed the tip and inserted a needle tip. I was able to slide one of those electrical black melt able insulating tubes over the tip and insert it into the worm gear. I oiled all of the wheel bearings, also not easily accessible, with a Labelle needle nose tube.
After thirty minutes of continuous operation the unit did not stall and both trucks created approximately the same amount of heat. Definitely less heat then previously reported.
Is this the problem, possibly... I run this engine a lot, pulling a pretty heavy load and driving up a steep 5% grade. The reference to the motor not getting hot is relative. by the time I take the cover off to check the motor it had probably cooled down. But it did not seem as hot as the trucks.
I also though it was possibly a low grade electrical short. I measured the resistance between the wheels and roller and the needle swung wide..
If you have the time and would not mind sharing some electrical information, my weak spot, I would be appreciative. How do you measure resistance? Yes, a meter I know but besides looking for the needle to swing wide or not swinging at all what are the norms for continuity between the ground and the positive. I have some weak spots on my layout. I can visually see where the engine slows but I can't measure where the week spot is. I get 18 volts everywhere. But, is it a resistance issue???
Thanks so much for your help....