Model Railroading > Athearn Motor Issue. (Resolved)

I'm curious if any of you have come across this "card in spoke" issue with an Athearn motor before.

I've shot this video I took before I disassembled the drive train to isolate the motor. The motor is most certainly the culprit. I can turn the motor by hand and can't sense any sort of binding that way. Removed motor and inspected. Nothing fowling the motor. Reset it in the mount and frame. No luck. New Genesis replacement is on order but I'm wondering if anyone has come across this before. It's a first for me.

Athearn RTR SD40 with Tsunami sound.
Original motor # 84080
Genesis upgrade # G63839



Edited 1 time(s). Last edit at 05/03/25 14:37 by ChrisCampi.

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Sounds like something is hitting as it spins

Posted from Android

Interesting.   You said with the motor removed it looks fine, but did you test run the motor in your hands?   To make sure it was not something else in the drive?
Rich.

ATSFSuperCap Wrote:
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> Interesting.   You said with the motor removed
> it looks fine, but did you test run the motor in
> your hands?   To make sure it was not something
> else in the drive?
> Rich.

I removed everything but the fly wheels, then remounted the assembly in the frame to test it. It's the motor assembly for certain. I'll investigate further when I replace it. I spun it by hand while holding it in my other hand, but I did not apply power while holding it. The locomotive frame is not impeding the motor assembly in any way.

To be perfectly clear, the noise occurs without the drivetrain connected to the motor assembly in any way.



Edited 1 time(s). Last edit at 04/25/25 18:29 by ChrisCampi.

SPDRGWfan Wrote:
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> Sounds like something is hitting as it spins
>
> Posted from Android

Yes it does.

Have you tried testing for a broken/cracked geared axle to eliminate that cause. Just a thought.

Check your universals, something may be out of alignment

milwaukeemike Wrote:
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> Have you tried testing for a broken/cracked geared
> axle to eliminate that cause. Just a thought.

"To be perfectly clear, the noise occurs without the drivetrain connected to the motor assembly in any way."

chitownjeff Wrote:
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> Check your universals, something may be out of
> alignment

"To be perfectly clear, the noise occurs without the drivetrain connected to the motor assembly in any way."

I had the same problem the loco just ran slow I change the motor cleaned every thing cleared the truck contacts and decoder, finally found a old sd45t-2 and switched out the hole bottom runs prefect. I have no idea why it would not run right.

Dave

bnsfmodeler Wrote:
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> I had the same problem the loco just ran slow I
> change the motor cleaned every thing cleared the
> truck contacts and decoder, finally found a old
> sd45t-2 and switched out the hole bottom runs
> prefect. I have no idea why it would not run
> right.
>
> Dave

Huh. Thanks for the feedback Dave. When the new motor arrives, I'll disassemble this one and see if I can spot something.

flywheel is hitting the frame

The motor does seem a bit tilted toward the rear and that makes me suspect that flywheel may be rubbing the frame. I would run the motor outside of the frame to see if there is a issue. Other than that maybe a issue with one of the magnets where the armature is hitting it. I've seen magnets swell like zinc pest before in cheap motors.

Ted Curphey
Ontario, OR

Don't know what's going on in this example but I have put some oil or grease at the point where the motor shaft passes through the metal frame. Not sure what is in there but it seemed to have swollen and put a load on the motor, didn't make a noise, just high current and low speed. Had a long, very narrow applicator on a hobby motor lubricant, perhaps Atlas or similar, that fit between the flywheel and the frame.

It seemed to work, then tried it on other motors but the oil appeared to dissipate after a while. then began looking for replacement motors, then new projects came up so I reached out and put it on the shelf. Problem solved.

original Wrote:
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> flywheel is hitting the frame

Boy, I  just not seeing it. If one is, it's out of round which makes it a poor flywheel. I'll take another look to see if the flywheel is maybe not mounted to the motor shaft properly.



Edited 1 time(s). Last edit at 04/26/25 12:27 by ChrisCampi.

funnelfan Wrote:
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> The motor does seem a bit tilted toward the rear
> and that makes me suspect that flywheel may be
> rubbing the frame. I would run the motor outside
> of the frame to see if there is a issue. Other
> than that maybe a issue with one of the magnets
> where the armature is hitting it. I've seen
> magnets swell like zinc pest before in cheap
> motors.

I saw the tilt also and remounted the motor twice. I think your correct in that something is going on within the motor itself.

Take the motor out of the frame run some test clips to the electrical inputs and see if it makes the noise out of the frame. If so it's either brushes or a armature piece hitting the motor shell. ---  Ken 

Just remembered I had one motor where the tabs next to the commutator plates were not bent over correctly, kinda remember it was making a noise or maybe jamming. It didn't do it out of the box but once it loosened up enough the tabs began hitting something on the motor frame.

Comparing that motor with other Athearn motors the tabs were shaped differently, I kinda remember the tab was meant to hold the motor winding wire in place.

Hi Chris, I don't know how easy it would be to do, but perhaps a video of the motor disconnected from the drivetrain
and with the shell set aside would help focus the trouble to the motor. (I couldn't do a video myself soooo...) 
But when watching the video the sound seems be a rattle from something hitting the shell. You say that is not in fact True but we
only have the video to watch and the shell and drive train are there spinning and touching.  
The suggestion of running the motor removed and isolated to in hand is a sound suggestion. And the new motor will
likely fix it. But, Athearn although considered somewhat bulletproof, do seem to have a penchant for odd noises. The
Good news is supposedly the new motors are better motors. Looking forward to what you find.

inyosub Wrote:
-------------------------------------------------------
> Hi Chris, I don't know how easy it would be to do,
> but perhaps a video of the motor disconnected from
> the drivetrain
> and with the shell set aside would help focus the
> trouble to the motor. (I couldn't do a video
> myself soooo...) 
> But when watching the video the sound seems be a
> rattle from something hitting the shell. You say
> that is not in fact True but we
> only have the video to watch and the shell and
> drive train are there spinning and touching.  
> The suggestion of running the motor removed and
> isolated to in hand is a sound suggestion. And the
> new motor will
> likely fix it. But, Athearn although considered
> somewhat bulletproof, do seem to have a penchant
> for odd noises. The
> Good news is supposedly the new motors are better
> motors. Looking forward to what you find.

When the new motor arrives, I will most definitely video the old motor all by its lonesome on my workbench. :-)