Thanks, all. With all our can motors, I forgot the basics of dried armature bearings after 20 years. Two drops medium light oil bottom and top on all now. The jam turned out to be the magnetraction having picked up a sliver of some broken metal from between the ties, and that jamming the gears on the one truck. I removed motor and checked grease in the slowest-running truck/motor and the grease is still in great shape. The board heat sinks are just comfortably warm after 10 minutes running in on rollers. Still at it, amp draw gradually coming down. In conventional mode, exactly 1.25 amps per motor now, still running. Wires are good quality, still very soft even with age.
Any comments on how many minutes or hours of running in motors of this vintage need to get as smooth as they are going to get? I don’t have much experience with them.
