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Discussion Starter #1 (Edited)
Afternoon Everyone, I'm new to the board so I apologise if this has been posted in the incorrect area. A quick search didn't bring up anything similarly related.

I recently purchased a "new" old Bachmann Spectrum Light Mountain 4-8-2. It's DCC ready but is currently running in DC mode as I've not yet converted my simple layout. I've got an issue with it that has me completely stumped. When running forward, the loco has a very slight squealing noise coming from the motor/gear area. It's most noticeable at low speeds. At mid speed to high speed, you really don't hear it at all. In reverse however, it's much worse. This is amplified by the fact that due to limited space in my home, may layout is attached to a large fold up oil painting. Boy do I wish I'd put some cork down!

  • Every moving part on the loco has been oiled, so far as I can tell. I've completely taken it apart and rebuilt it again. (A mix of Labelle 106 and 102 depending on application)
  • I've cleaned the gears best that I could. The oil had all run to one side, I assume from the loco being stored in a box for years. While I can't be certain, I have a sneaking suspicion, someone in the past used lithium grease. Although the loco looked untouched, the grease in there sure looked like Lit. Grease to me.

  • Here's what I've managed to figure out and I'm just so frustrated at this point.... This locomotive is belt driven. There is a small brass worm gear (?) that protrudes from the body. When this is detached from the wheel chassis it's just a nice quiet whurr from the motor. When you place the body back onto the wheel chassis and it connects to the single white gear (which is attached to one of the locomotive wheels) the noise returns. This got me thinking that it was probably a simple lube issue. Nope, even with lube, the noise is still there.
To make matters worse, because the tender is fairly hollow, it almost acts as a speaker, amplifying the noise. I had wondered if perhaps the belt was rubbing against something. But I took a look at the belt with a jewelers loop and there doesn't appear to be an rubbing wear.

Outside of the noise, the loco runs great and is a strong puller.

So, I've decided to turn to the internet experts because I'm totally stumped! Experience level is about 12 months worth. I know more about computers than I do about simple gears. I'm hoping someone else has run into this issue.

(Please see attached image for reference)


Thanks!
 

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Several possibilities. Flashing on plastic, or maybe a wire too close, near something turning quickly, like a prop shaft to a gear tower or maybe the much larger flywheel. The motor mounts and components of the drive near the gear tower really do shift some, depending on the rotational direction of the can motor. Or, it's just a dry bushing. It won't be a dry gear...pretty sure, but anything's possible.

The bearing cones in the tender and loco trucks can sometimes get bits of grit or plastic, or even single fibers from carpeting, clothing, pet or human hair....the list is almost endless. Or, they are imperfectly conical. Micro Mark sells 'The Tool', as it is called, a reamer for that application. Like the scale NMRA track gauge, it's a must have if you're buying rolling stock.
 

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Is it "DCC Ready", or "DCC On Board"?
Some Bachmann locos were mislabeled, and many of the DCC-on-board decoders can make a squeeling or 'scratchy' noise.
 

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Discussion Starter #4
Several possibilities. Flashing on plastic, or maybe a wire too close, near something turning quickly, like a prop shaft to a gear tower or maybe the much larger flywheel. The motor mounts and components of the drive near the gear tower really do shift some, depending on the rotational direction of the can motor. Or, it's just a dry bushing. It won't be a dry gear...pretty sure, but anything's possible.

The bearing cones in the tender and loco trucks can sometimes get bits of grit or plastic, or even single fibers from carpeting, clothing, pet or human hair....the list is almost endless. Or, they are imperfectly conical. Micro Mark sells 'The Tool', as it is called, a reamer for that application. Like the scale NMRA track gauge, it's a must have if you're buying rolling stock.
Phew, lots of phrases here I'm not familiar with but I'll pick apart your post and attempt to check everything one by one. I greatly appreciate you taking the time to reply. Typically when a loco like this gives me grief, I'll ebay it, but this is such an awesome looking steam engine, I'm determined to get it running smooth.
 

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Discussion Starter #5
Is it "DCC Ready", or "DCC On Board"?
Some Bachmann locos were mislabeled, and many of the DCC-on-board decoders can make a squeeling or 'scratchy' noise.
I'm fairly certain it's DCC Ready as are most of my engines (in preparation for switching to DCC). I did take the shell off the tender and it has the "placeholder" chip similar to what's in my Proto 2000's. It doesn't appear to have a decoder. With that said I'm 95% sure it's coming from some place between the engine and gears.

Interesting thing is, if you run the wheels on the track without the metal body and engine, it's quiet. Run the engine and body without the wheels, it's just a humming sound. Put them together and tada, noisey, especially in reverse.

I'd be willing to post a video if anyone thinks it might help.
 

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I am taking a guess ... but if it is a older bachmann it has a split drive axle. The drive gear is probably cracked & slips at lower speeds to make the noise. At a faster speed the gear warms a little & grips to quiet the noise.
Again I could be wrong on this. However it just seems like what you described is what I have seen with my older bachmann steamers.
The drive gears where known to crack


Sent from my iPhone using Tapatalk
 

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Discussion Starter #7
I am taking a guess ... but if it is a older bachmann it has a split drive axle. The drive gear is probably cracked & slips at lower speeds to make the noise. At a faster speed the gear warms a little & grips to quiet the noise.
Again I could be wrong on this. However it just seems like what you described is what I have seen with my older bachmann steamers.
The drive gears where known to crack


Sent from my iPhone using Tapatalk
hmm given that I've cleaned and oiled just about everything (as you can see from the image I attached, this is a fairly simple system, there's only a single gear), I do wonder if perhaps there is a crack. I had a Proto 2000 with a cracked gear though that was more of a click. I'll check it again with a jewelers loop and see perhaps I missed something. I hope not! That single gear looks like a pain to replace.
 

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Discussion Starter #9
Hello Everyone,

I wanted to take a quick moment to update on this for future searchers. I manage to solve the problem.

There is actually nothing wrong with the locomotive but I'll try to do my best to explain what's going on. Last night I completely disassembled the locomotive. I separated the body from the wheels/drivers all the way down to the motor. Interestingly, the motor, sitting within the metal body, when given power, was silent. I had an idea to place my metal tweezers (they're fairly large) gently on top of the metal body and on the tender. The moment I did this, you could hear the noise. Given that the motor is running on it's own, this made no sense. Until I realized what's happening. Basically, the motor has it's own noise, though functioning just fine. The body shell and tender are acting as amplifiers/speakers. What you can't see in my video above, is that the train (sitting on the tidy track) is actually placed on top of a large oil painting folded down from the wall. THIS also acts as an amplifier because it's bolted to the stud. Making the sound far worse than it really is. Just a perfect chain of events really.

So... I had a little cork in the garage. I placed the train and tridy track as shown in the video, on top of the cork and...fairly silent. My solution was to remove the motor completely from the body. I then determined any place the motor actually touches the metal body when clamped back together and added small bits of electrical tape. The thought behind this was that the electrical tape would work to dampen the noise/vibration. At this point, there is electrical tape between the body and the motor. I hope this makes sense.

At any rate, I put it all back together, double and triple checked all of the gears had fresh grease. At this point, the steam locomotive is running close to silent :)

So all in all, a perfect set of events it would seem leading up the noise. I greatly appreciate everyone's help and input, I hope this will help someone in the future.

Side Edit/Observation:

Interestingly enough, I have another Bachmann Spectrum I don't run too often. It's a GE 44 Ton Switcher (DC). I placed that onto the track and you know, it makes a very similar noise! But, when placed on cork, it's silent. This must just be the way these motors sound as the GE 44 Ton Switcher has a very similar motor inside. I thought perhaps worth mentioning for this goes into the deep archive.
 

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I'm glad for two reasons: one, you took the time to get your fingernails dirty...you actually took the locomotive apart. Secondly, you figured out what the noise generator was, and you are now going to be both better experienced and happier with what you have. You really like the steamer, and now you can enjoy running it. So, good for you.

I'm a little unsettled by the rocking motion of the chassis when the drivers are turning. Is this the roller mechanism, the test bed? Or, is your locomotive waddling down the rails when it is on them?

I ask this because, aside from the whirring noise and the rocking, there's also a periodic click, and this usually means either a gear beginning to come apart, a pin or rod making contact as it revolves with the driver and meets another rod or pin,....or....the locomotive is slightly out of quarter. Well, there's actually another, and that is that one or more of the driver axles is bent. Oh gosh...I can think of one other very rare case I read about...a driver mounted on its axle off center slightly, or not parallel to its opposite.

My question is moot if the loco runs fine on the rails. It's just the test bed roller that make it waddle.
 

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Discussion Starter #11
Thanks for the kind words! Totally worth the trouble. I wish I could say it was all smiles, but there was some frustrating points when putting things back together!

As for the wobble, you're correct in that it's slightly out of quarter. The tidy track cleaner (which I use more for testing than I ever actually do for cleaning) has a center rail area that's just slightly too big. As the loco is wobbling a bit, the wheel is sliding up and down the center "track" if you will. Once it's on the actual track, there's no clicking at all.

But, at certain speeds, the hunting is noticeable. Visually, the wheels look to be in quarter, but obviously, something's not quite right. I've quartered wheels one time on a Hornby steam engine, it was a tricky process but those things are built like tanks. The bachmann, I'm a bit more hesitant, though willing to quarter the wheels.
 
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