I am still having a problem with my Bachmann 4-8-4 Niagara front pilot. It will not stay on the track. Yes the wheels are in guage, yes the track is in gauge, Yes I tried adding weight to the pilot trucks, I even lubed it with Labelle 108 Grease, the pilot still won’t stay on. This is the only steam unit I have trouble with and Bachmann has never replied beyond suggesting the three steps already done. I realize most will say Bachmann is no good, but I have the War Baby GS-4, also a Northern type, and it hold fine. I am open to [:(!] any suggestions, short of junking the unit. This has been going on for over a year now.
Where does it derail, anywhere on the track, or only over switches?
Have you checked the wheels for broken or misshaped flanges? A little chunk missing from a wheel flange would make it hop off at various time.
If only over switches, it could be the flanges bottoming in the frog. Or too sharp a flange picking a point. Since you say the wheels are in gauge, I assume you have an NMRA gauge to measure that with - check the flange depth and flange countour as well.
Also check for excessive free play in the pilot axles. Especially fore and aft, if the two axles can move realtive to each other, they could be created a ‘steering’ effect that will steer the pilot right off the track.
I don;t have either model, so I don’t know how difficult this might be, but consider swapping between the Niagra and GS-4 and seeing if it is the pilot itself or something in the engine dynamics.
–Randy
It derails anywhere-straight-aways, mostly on a curve-any curve, and actually tracks over turnouts well. I thought of the pilot swap but they are two different configurations and are definitely not compatible. There is no freeplay like you suggested in the current pilots. Wheels are in fine condition, i.e. no chips our gouges. Yes I have the NMRA Gauge-in fact I bought a new one just in case my old one was out of whack. It’s a mystery-like I said-even BAchmann won’t reply anymore and teh unit is only about a year old.
How is the front truck mounted? I don’t own this particular model, but I have nearly every Spectrum model that Bachmann has ever released. If the truck has its mounting screw right in the middle together with a cone-shaped coil spring, the ends of the spring may be snagging on something. Try running the locomotive without the spring. If the truck is mounted from the rear with a tongue, make sure there are no burrs on the tongue, screw, or locomotive body. Also check that the screw is not too tight and causing the truck to bind. This is probably too obvious to mention, but make sure you don’t have the truck on upside down. I know this sounds silly, but I have seen people do this to other models and wonder why they won’t stay on the track.