# #300 loco went from running great to binding!



## ChopperCharles (Jan 3, 2012)

Was running my #300 loco today. It was running at full speed, going around the track at a good clip, and then suddenly nothing. Lots of buzz, but no forward movement. I took it down and took it apart as much as I can. The chassis doesn't split on this model, so I see no way to remove the wheels except for pressing them out... well the problem is the drive wheels with the gear in the center, they're completely bound up. I can turn them (armature and all linkages removed) by hand with great force, they should free wheel like this. i see no obvious damage to the gear, any ideas what could have happened? There's plenty of fresh grease in there too!

Charles.


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## ChopperCharles (Jan 3, 2012)

Compared against the 21160's gear, there's definitely no tooth wear. Feels for all the world like a bearing seized up. Do these even have bearings for the drivers? I know the later models don't...

i'll get the arbor press out and push the wheels apart tomorrow I guess. Damn, this was a fine-running loco just 20 minutes ago 

Charles.


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## Reckers (Oct 11, 2009)

Charles, try taking the side rods off and see how it runs. I don't know how it might have happened, but that may be the cause: they might be out of sequence or one may be getting jammed in the steam chest.


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## ChopperCharles (Jan 3, 2012)

I already said I took the linkages off, I stripped the chassis down of everything that could be unbolted and easily removed.

Charles.


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## AF296 (Feb 29, 2012)

Sounds like a quartering problem. What may have happened, is the drivers were out of time just a hair. In any event something bound up. When this happens at full speed you probably bend the axle in the chassis or a side rod.. Is the drive gear still in the center of the axle The drivers on one side must be 1/4+ turn past the drivers on the opposite side. If the drivers are not quartered you'll have to pull them and reset them.. If the axle is bent, which I think is the problem here, you will have to replace it..


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## ChopperCharles (Jan 3, 2012)

Side rods are currently removed, but they were properly quartered. Nothing was bent, and the rods weren't bound up at all when I pulled it apart. They all still wiggled on the wheels. Now that the side rods are removed, the wheels are bound in the chassis. I will press the axle out later today and check what's up... why would an axle just bend if the quartering was fine? 

Charles.


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## tjcruiser (Jan 10, 2010)

Maybe the loco picked up some debris which lodged in the gear teeth, causing a sudden stop, but momentum cause distortion somewhere? Perhaps the debris is now gone, with the teeth looking OK?

Just tossing out a theory ...

Check the axle bearings, too.

TJ


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## ChopperCharles (Jan 3, 2012)

Well, I took it apart today. Once I pressed it apart, it freed up whatever was jammed. I disassembled everything, looked for metal shavings, pressed it back together, and it works again. I didn't do anything special, just took it apart and put it back together again, even marked the axle and the wheel so the quartering is the same. It's back to running perfect again. Weird. 

Charles.


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## gunrunnerjohn (Nov 10, 2010)

Don't worry, it'll happen again!


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## Big Ed (Jun 16, 2009)

gunrunnerjohn said:


> Don't worry, it'll happen again!



I had a loco like that ( O) and it was a bent chipped gear.

But I guess he looked when he had it apart?

I didn't want to ask, but figure I would mention it.


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## ChopperCharles (Jan 3, 2012)

No bent or chipped anything, I checked for that, it definitely wasn't the gearing system, as I removed all gears and everything from it. I did notice that if I press the axle in too far on one side it starts to bind, and there were wear marks on the case, as if the wheels have been rubbing. When I removed the loco the wheels had zero side-to-side play, now they're gauged properly with a little side-to-side wiggle. if it happens again, it happens again, and i'll replace the axle and see if that fixes it.

Charles.


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## gunrunnerjohn (Nov 10, 2010)

Just giving you a hard time Charles, don't take it to heart.


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## ChopperCharles (Jan 3, 2012)

heh, noted. I'm three beers in now and much more amicable, let me tell you 
No harm no foul, bring it on 

Charles.


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