AZL SD70 Noise

cthomz Aug 16, 2014

  1. cthomz

    cthomz TrainBoard Member

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    I recently purchased a CSX SD70 and upon testing, found it to be incredibly noisy (especially compared to the GP7 or even F7). I disassembled and reseated the trucks, however it is still the same. I even let it run for quite some time assuming it just needed to run through a break in. The noise is amplified when running it with the shell on. Any thoughts would be greatly appreciated.


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  2. ddechamp71

    ddechamp71 TrainBoard Member

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    Was this loco purchased brand new?

    Dom
     
  3. cnrtcmtl

    cnrtcmtl TrainBoard Member

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    Just go 2 ATSF SD75
    Both are running fine without any noise...???
    My only question the red of the ATSF and the on on the BNSF warbonnet is not the same
    The one on the ATSF is lighter...? Rob ? Is that OK ?

    Ray
     
  4. MRL

    MRL TrainBoard Member

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    If it's ran in the desert for a few years or is running with a BNSF motor it should be fine.
     
  5. DSZ&N

    DSZ&N TrainBoard Member

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    Hi Cthomz, I have had a couple of the newer SD and GP that were Loud. What I found was the Plastic bushing that sits between the frames and holds the worm gear in place had a big piece of flash left on it. what that did was make the worm gear shaft go out of round. this makes the connection to the motor very unhappy. the motor has a cup with 2 noches cut into it that the worm gear shaft seats into, if it is out of round it will make a grinding sound. shave the bushing (it's on the OD of the bushing) with a razor blade. just the flash don't want to make bushing smaller. it will run much quieter and smoother
     
  6. cthomz

    cthomz TrainBoard Member

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    Yes it is brand new, right out of the box.


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  7. cthomz

    cthomz TrainBoard Member

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    Thank you for the advice. I will disassemble again and see if mine has a similar issue.


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  8. DSZ&N

    DSZ&N TrainBoard Member

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    One other thing I forgot to mention. When you have it apart make sure the "T" section on the end of the worm shaft is pushed all the way on. If not it will bottom out on the motor fly wheel. Hope you get this before you reassemble. hope it works for you.
     
  9. ztrack

    ztrack TrainBoard Supporter Advertiser

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    I have not compared the red between the BNSF and ATSF runs, but it is possible they will be different. The new ATSF run was done by a different manufacturer. Each used their own mix of red so I am not surprised the ATSF may be lighter. But in real life, the red did fade to pink so lighter is not a bad thing!

    Can someone take a photo of the flash on the busing and send it to me? I know after running the locomotives for a while will diminish the sound. Likely the flash is being worn away. But I curious on the amount of flash.

    Rob
     
  10. DSZ&N

    DSZ&N TrainBoard Member

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    Sure Rob, I'll try and find one today. Need to go through my SP SD's today haven't run them yet so not sure if ill have the problem.
     
  11. DSZ&N

    DSZ&N TrainBoard Member

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    Here is a sample of the flash I'm talking about it has another on the opposite side. this is not all that bad I've had a couple that were much bigger. it might be as simple as rotating the flash so it aligns with the split in the frame.
     

    Attached Files:

  12. goobnav

    goobnav TrainBoard Member

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    Thank you Dave, I suspected that's what it was, I have a NS GP38 that is doing the same thing, hope it works out.
     
  13. DSZ&N

    DSZ&N TrainBoard Member

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    Couple of things to keep in mind. Motor and drive shafts are the big difference between the old SD run and the new run. The trucks have been greatly improved with the new coupler design.no more glue :) . when I got my first really noisy engine first thing I did was pull the trucks and put them on one of my old silent engines (wanted to see if they would fit as well) and fit they do, The engine is still silent so going to say noise is not from the trucks. The motor has been down graded to a china can motor in stead of the Swiss engine on the first run. while I don't care much for the running performance compaired to the Swiss engine I would think the motor would make more noise at low speed where it is getting much louder at the top end. Engine is really silent below 1/2 throttle. The old drive train had the worm gear shaft connected to the flywheel with a piece of tubing. I believe this allowed for some forgivness in any misalignment of the motor to the worm gear shaft. But for some reason they only put the bushing on the outside of the worm gear. on a plus note the bushing had a bronze insert for the worm shaft. the new design is more of a solid connection. the end of the worm gear shaft has a plastic T shaped coupler that fits snuggly in the flywheel. This design is much more critical to everything being in proper alignment. The last thing to note is the bushings on the new design are all plastic. there is no bronze insert in the new design but they did put a bushing on each side of the worm gear but only put a washer on the inboard side of the worm gear. These are just some of my findings if you have any thing else to add please do if you feel I have made a mistake please lets discuss it.
     

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