I have a few of the Atlas SD-24’s, the UP’s and ASTF’s as well as the BN unit.
All the units run fine, though terribly out of gauge, exspecially on Atlas code 55 turnouts 
I just purchased another SD-24 the other day (ATSF 927) and have ran it around the track at half speed in both directions for about half an hour. I also dabbed a super small amount of Labelle 106 on the upper gears.
I runs very rough at slow speeds, and will just sit there with the lights on at 1/4 throttle while the other ASTF unit runs fine in the same ranges.
Do I have a lemon? Or is it just needing more breaking time? The others ran perfect out of the box/case, this one is not as snappy.
I am impressed with the Atlas loco’s they seem to have a much better slow speed steadyness as apposed to the KAto’s I have.
Thanks!
Dave