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Diesel Locomotive Maintenance

santafe loco

Club member Angelo sent in these tips to share:

Anything with moving parts can experience problems from time to time, and locomotives are no different. To ensure smooth reliable running they need some care and attention. Here are 4 common problems and common causes:

  1. Poor Performance: Inspect for dust, dirt, hair particles, or a build-up of crud.
  2. Tight or Worn: Check for any damaged or missing parts. Inspect the springs and carbon brushes.
  3. Smoking or Sparking: This could be an indication of too much grease and/or oil.
  4. Wheel Alignment: Even if the wheels are in gauge they could be misaligned front to back. The universals could be misaligned.

Here are some more things to check:

Watch and observe (keep a record) of how the engine operates in both directions and at different speeds. Listen carefully to the engine sound (noise). You might discover the loco runs better in one direction and no so well in the other direction. It may also be noisier in one direction than the other. Also, check for any slack around the thrust washers. The wheel treads should be clean.

The wheelsets might have a coating that won’t conduct electricity. One option is to put the wheelset into an expandable truck frame and then burnish the wheels using a brass brush attached to a Dremel motor tool. You might already use a rotary brass brush for cleaning solder from your nickel silver frogs so this is another use. You can also buy packs of 3 brass brushes (they look a bit like toothbrushes) from Discount Stores for about $5.  A Dremel brush can be used when the engine is running while resting on its back. Those with DC could use a Kadee wire brush. Alcohol (70% isopropyl alcohol) is an effective cleaner.

If you notice the locomotive movement is somewhat “jerky”, it could be caused by a tight part or by poor electrical contact. A diesel engine might not have enough play in the drive train, or if it’s a steam engine it might have binding in the siderods.

Also inspect the wipers. On some locomotives you’ll need to check the seating between trucks and chassis. Electrical pickup will rely on the mechanical connection at this point. Another piece of maintenance is to polish around the “king pin” where the truck swivels, and on any contact surfaces.

inside model trainSmoke could simply be a sign of too much grease/oil, or it the motor overheating. This could be result of parts being too tight, or be an indicator to other problems. To check if it’s the motor, firstly remove the couplings to run a test on the motor free of any connections. Listen out for any clicking from the drive train. Sometimes a tiny particle of flash can get on a gear. You might need a microscope to see it, but it can settle at the bottom of the valley between the teeth. Use a pick or small file to remove any flash. Another possible cause could be a tiny speck of metallic ballast that has been picked up. Commercial ballast should have no magnetic debris in it, but real dirt could have some iron in it.

If you notice the speed is inconsistent it could be caused by a faulty “u” joint or loose tubing if it was used for coupling to the driveshaft.

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3 Responses to Diesel Locomotive Maintenance

  • Newman Atkinsonsays:

    These are a lot of good tips. Also taking your older engines and adding new DCC Chips to them and especially adding ones with sound, find trying to fit all that in will take up all that room you thought you had and make it a squeeze play to get it all in your engine body. Taking your time and plan where everything will fit will help a lot. That speaker if you are adding sound might just be the one that pulls your hair out to get it to fit. All these wires, speaker and chip will challenge you to fit it all in and not rub a flywheel, or contact. One of the biggest items I have found is something rubbing a wheel truck or something on it keeping it from turning or swiveling to stay aligned with the tracks. These are some small but added issues that will give you problems.
    from Newman Atkinson

  • Colinsays:

    Obvious one I know but keep your work area completely clean. I once was fitting led’s to an old Class 37 I had freshly converted to DCC and the magnetised wheels had unknown to me, picked up one of the legs I’d snipped off earlier to shorten the LED. As soon as I placed the engine on the track there was an audible pop and the decoder went to the DCC graveyard in the sky. Always know where your debris is and dispose of it straight away folks 😉

  • Mike Leesays:

    All comments excellent. I would add if you have done all of the above and you motor draws a lot of current compared to your other engine motors then have the motor re-magnetized. This really brings them back to life. The running current can drop to 20% of not magnetized motor. If you can find a Slot Car Shop where they race that shop will have a small motor magnetizer.

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