# Locomotive derailing



## Pastorjones (Jan 21, 2011)

I have a bachmann 4-8-4 steam locomotive that came in my overland limited set. The rear wheels derail all the time for no reason whether I run it by itself or with rolling stock. All track connections are good. Is there a "home" remedy for this? I've been calling the manufacture been it's been phone tag.


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## tjcruiser (Jan 10, 2010)

Check the gauge of the rear wheels / trucks ... i.e., the specific wheel-flange to wheel-flange distance. Does it appear wide at all, with the wheel flanges riding up on the rails a bit?

Also, check the freedom-of-motion of the rear truck. It should pivot left/right and have a bit of up/down play, too ... sometimes with a spring to give it a little down pressure.

Does the derailing happen only on cuved track? Switches? Straight track? If curved track is the problem, what track radius are you running on?

TJ


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## shaygetz (Sep 23, 2007)

The rear truck (the last -4 in 4-8-4) is mounted in an odd way that's fairly unique to large Bachmann steamers. Rather than a hitch on the front of the truck similar to trailers, allowing it to follow the locomotive, their engineers used a sprung centrally located pin we oldtimers refer to as a pogo stick, forcing it to pivot and swivel around itself. Its design meant well but doesn't give the necessary flexibility on the tighter curves that come with those sets. A bit of fiddling with the spring to loosen it up will help, just don't over do it.


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## tkruger (Jan 18, 2009)

I have a Bachman 2-6-2 and the rear truck is just as Shaygetz states. I had to loosen it to make it work. It would not trail properly when I first received it. In addition to this it is to light with to little down force on it. If there was any irregularity on the track it would cause it to 'hop' off of the track. This was especially true on snap switches. I had to bend it a little to make it work on mine. Yours may be different though weight wise since there is an extra axle.


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