# Athearn RTR SD40-2 buzzy motor.



## dalehenigman (Aug 21, 2014)

I have an Athearn RTR SD40-2 and the engine will run a little bit and then it slows down and makes a buzzing noise. Have narrowed it down to I think to be a defective motor. Oiling motor bushings helps for a while. I called a motor repair shop and he said it is possible for the motor shaft to vibrate in the bushing bore. I have seen larger motors do this........Opinions?........Thanks...Dale.


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## wvgca (Jan 21, 2013)

yes, it's possible for the motor shaft to vibrate within the bearings , although not very likely unless it has a whole lot of hours with no or little lubrication ..
what is more likely, is that the lower mount [semi rigid plastic] has gotten firmer [and slightly smaller] with age leading to unwanted vibration.. they are pretty cheap to replace, ideally from a dealer as they would have the 'freshest' ones ..


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## Dennis461 (Jan 5, 2018)

If the motor is held in with plastic tabs, they may be dried out and letting the motor rise up in the body. When this happens, something (perhaps a wire) touches the body which amplifies the sound. My SW7's are very close tolerance inside.

I have replaced most all of my Athearn blue box plastic tabs to stop buzzing.


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