In response to KRM’s mention of his 6-18406 Maintenance Car running poorly, I thought I’d try to make a short video of mine, and what I did to it. All one take, off the cuff, complete with poor lighting and shaky camera work!
For what it’s worth, it seems like Lionel had some issues with gang cars grounding through the bumper slider during the postwar era, because there’s a note about it in the service manual:
This does seem to suggest that the re-designed grounding spring did improve the grounding of the car. However, the blacked frames definitely do conduct electricity to some degree, whereas the painted frame of the 6-18406 definitely insulates the bumper slider.
Between the basic mantenance, extracting all the old lube and replacing it with new, and scraping the paint off of the points where the bumper slider contacts it, I ended up with an extremely reliable runner, that runs just as nicely as a good postwar piece.
Hope this is helpful to anybody with a 6-18406 of their own!
-Ellie