Sent yet another 3927 track cleaning car to Harmonyards for repair; Pat is excellent at repairing these cars; bought this one from the Bay; on the outside it looked pristine but it ran intermittently; on the inside, Pat found a broken brush spring, worn brush, the washing head gear, part no. 3927-10 has a broken clip internally, a break in one commutator segment, right at the solder lug - all repaired and on its way back to me. Here are some pics and video:
Smooth as butter for a 1956 Lionel motor!
Happy Camper!