Problems with a Bachmann 70tonner

  • Thread starter FireDragonLightning
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Hi! Maybe someone here can help me... I will not be buying any more Bachmann stuff after this problem. I've emailed their customer support three times! And the 'free repair' warrenty is almost up!

Here's the diagnosis:

HO Scale GE 70-ton Diesel switcher, Orange/Black, Southern Pacific, Engine number # 5104.

GE 70-ton Diesel switcher which will not run when placed on a layout and power is applied. The engine just sits there, creating a humming noise. Occasionally it may move extremely slowly, more like the vibration of the motors are inching it forward. I can't see anything wrong 'under the hood'... If anyone here has an Idea I can take photos of the model. It was brand new last November, no reason for it not to work.

Any help appreciated! Thanks! :D

Edit: Should add that it is a Spectrum engine
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I would try going to a local hobby shop to see if they know. I have heard Bachmann dosen't have good quality.



Registered Member
Staff member
Hi FireDragonLightning, I'm not familiar with the Bachmann Spectrum, however I doubt mechanicaly they're much different than other quality locos. At this point if you have no support from the mfg. then you have little to lose by repairing it yourself.
1- Since the motor hums it must be getting current. ( I hope you haven't left it on long enough to burn) Therefore the problem will be mechanical!
2- Remove the Body shell, do an inspection to see if there is anything jamming the mechanism if so correct it and try the loco again. IF NOT
3- Remove the trucks from the frame ( universals and all) so there is no load on the motor except the flywheels.
4- Try turning the motor by hand, if it feels hard to turn then the problem is most likely there. ( not sure about Bachmann, but on Athearns I just increase the clearance between the motor shaft bearings and the flywheels) If lubricant is required for the motor bearings, get a plastic compatable lube from a hobby shop.
5- If the motor turns freely Apply a bit of power to the motor contacts, the motor should turn, if not! and its humming (sorry it's had it)
6- If motor runs good, then problem is most likely in the trucks. Test the trucks one at a time.
Here I'm not familiar with the Bachmann assembly SO!
7- If the worm was removed, when removing the truck from the chassis, you should be able to push it along a surface and the wheels should turn freely, if not dissasemble the truck to find out why it won't. If the worm assembly was not removed then you should be able to turn the wheels by rotating the universal attached to the worm.
I believe that's enough to get you started. If anyone is familier with this model please feel free to jump in and help :)

Cheers Willis

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