Frequently un-asked questions, or FUAQs include "Does the N50598 0-6-0 switcher tender have to be run-in?" And here the N stands for 9 millimeter track gauge. The 50598 stands for the manufacturer's model number. Switcher, is US for a UK Shunter, except in Pennsylvania where they are sometimes called Shifters. In Australia Shunters are sometimes called Yard Pilots. A Tender is generally speaking a fuel bunker.
Running-in with respect to motors is a period of uninterrupted operation in all
gears including reverse at moderate speeds so that bearings and contacts can
"seat" or get to know each other better. The point is the moving parts of
electric powered locomotives that run on N gauge track are tiny, and this means
tolerances between moving parts are also tiny which suggests that running-in is
kind of central to smooth running future operation.