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Athearn Genesis SD70MAC Grinding sound

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  • Member since
    July 2020
  • 42 posts
Athearn Genesis SD70MAC Grinding sound
Posted by Traincraft199 on Wednesday, March 30, 2022 8:58 PM

I just replaced the trucks on my genesis SD70MAC because the side frames were broken off the old ones. But now it makes an unsettling clicking/grinding noise when I run it, and sometimes it squeaks at higher speeds. I double checked to make sure no wires were rubbing on the shaft, and I put more than enough grease on the worm gear (labelle 106). The trucks are brand new and even had a bit of lube in them already, what should I do? I took a video of it here:

https://youtu.be/44pgJ1JtnGw

 

Building my first layout, 4x8 contemporary urban area in HO scale 

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Thursday, March 31, 2022 5:51 AM

Check the rest of the drive chain. Are motor mounts and bushing correct?

Run it with the body off to see what is happening. Maybe the gears have a different pitch.

Mybe there is a LION in there.

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    July 2020
  • 42 posts
Posted by Traincraft199 on Thursday, March 31, 2022 9:44 AM

I definitely think it's coming from the trucks. I tested the motor both by itself and with the drive shaft. I guess the motor could use a cleaning, but it didn't make the clicking sound I was hearing. as soon as I put the worm gear in and run the motor, the clicking/grinding sounds start again.

Building my first layout, 4x8 contemporary urban area in HO scale 

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Thursday, March 31, 2022 4:38 PM

There is probably a burr on one of the gears. Inspect the gears and remove any burrs very carefull, perhaps a toothpick can do it.

Or just run it in until the grinding stops.

New cars even into the 1970s requiored a break-in period where you had to drive at a lower speed for about 500 miles. Automotive gears were rough cast and you had to drive to polish the gears. Now everything is so finely engineered that this is no longer nevessary.

 

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    July 2020
  • 42 posts
Posted by Traincraft199 on Friday, April 1, 2022 6:00 PM

I opened both trucks and couldn't see any burrs, but it did look a bit dry so I lubed it more, still didn't get rid of the noise. But I noticed the trucks wobble strangely when I lift them off the rails:

https://youtu.be/t3n4kYx5p0A

No idea if it's related to the noise or not

Building my first layout, 4x8 contemporary urban area in HO scale 

  • Member since
    March 2019
  • From: South Lake Tahoe California
  • 188 posts
Posted by MetrolinkFan on Sunday, April 3, 2022 4:09 PM

Sounds like your drive shafts are a bit long,That go from he motor to the trucks. I had this issue I looked at the drive shafts,They were a lil tight on my athearn 6 axles.Engines so I trimed the drive shafts and the grinding noise went awa.But I am not sure what drive shafts yours ueses, I have a copule SD40-2's C44's.Mine were the drive shafts that did not have the lil prongs and the ends.You made need some shorter drive shafts,Hope this helps good luck hope you can fix your isses with your engine.My trucks did wobble like yours after I trimed my drive shafts they did not wobble anymore.

  • Member since
    May 2020
  • 1,056 posts
Posted by wrench567 on Sunday, April 3, 2022 5:54 PM

 Did the worm gear come with the trucks? Pop the top cover off and roll the truck without the worm gear. It sounds like there is a gear meshing issue going on. The worm may be too large for the worm gear. Or one of the idler gears could be bad. If the truck rolls easily without the worm then you know the trucks are ok.

    Pete.

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Tuesday, April 5, 2022 7:06 AM

Grinding Noise?

Perhaps your little conductor left his food processor turned on.

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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