I have a Bachmann DCC ready (straight DC) Alco S-4 that is about two years old. I noticed it needed some lubication after runnig it for a while. I removed the shell, loosened the circuit board that is over the flywheels by removing the two screws which hold it in place (did not remove the board) so that I could apply a small amount of plastic compatable oil (tiny amount) where the flywheels connect. I reassembled the locomotive by re-inserting the circuit board screws and reattaching the couplers (the shell comes off by simply removing the couple pockets). I then sparingly lubricated the axles where they connect to the trucks.
When attempted to run the locomotive, it ran extremely rough and I noticed that rear headlight was flickering even though the engine was moving forward (front light light was on). After a few minutes, the issued seemed to pass. The engine is now running smooth again and the flickering rear light is off when moving forward. Has anyone had this happen to them? If so, what would cause this? The only thing I noticed is that when reversing now both the front and rear lights are on (I don't remember if this was the case before). When running forward the front headlight is the only one on now.