# Engine revving up but loco barely moves



## daveben (Jan 30, 2021)

Help. One of my engines quit running but the motor revs as I apply power. Other locos run fine. I cleaned the wheels and the track but no joy. Have had the loco for several months and it always ran great. Does anyone have any suggestions?


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## CTValleyRR (Jul 26, 2014)

No suggestions, but a lot of questions: what model loco, what control system do you have, how are you applying power, and what do you mean by "quit running"? Presumably it no longer moves forward under it's own power, but are the wheels turning at all?

On the surface, I'd suspect a broken component in the drive train, but depending in other symptoms, there may be other things to check.


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## Old_Hobo (Feb 20, 2014)

Also, what brand of locomotive is it? Certain ones had broken gear issues…..we want to help, but need more info, pics even….


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## T-Man (May 16, 2008)

How about a lost traction tire?


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## DonR (Oct 18, 2012)

Help us help you.
Give us some answers.

Is the loco a Steamer or Diesel?

Does the loco drive wheels turn but
do not move the loco...wheel slippage?

Do some 'drive' wheels turn but not 'all'?

Does the motor run but no wheels turn?

Don


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## MichaelE (Mar 7, 2018)

T-Man said:


> How about a lost traction tire?


Do they use those on N scale locomotives?


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## T-Man (May 16, 2008)




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## daveben (Jan 30, 2021)

DonR said:


> Help us help you.
> Give us some answers.
> 
> Is the loco a Steamer or Diesel?
> ...


Yes more info would help. It is a Kato Diesel. The front 4 wheels turn but do not move the loco. The back wheels do not move at all. The motor whirls as if it was moving. It moves a few inches and stops.


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## pmcgurin (Sep 7, 2010)

I have had Kato locos, mainly F3s where I had to replace the trucks to get the loco to run. It wouldn't move well. In these cases the locos had a lot of run time, and replacing the trucks solved the problem. These were mid 1990s F3As.


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## Chops (Dec 6, 2018)

Going to be less than no joy. Split gear? Not my pay grade, but walks like a duck....


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## Mixed Freight (Aug 31, 2019)

High probability it has a split, or otherwise slipping, coupling between the motor and the rear gear tower. I've seen this before, albeit mainly in other brands besides Kato.


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## timlange3 (Jan 16, 2013)

If the motor spins but some wheels don't move I would suspect the motor shaft is spinning inside a gear that should be attached to the shaft. A good cleaning and appropriate glue should fix that. But also check that the gear and the wheels it is attached to spin freely. Maybe something is binding that caused the gear to break loose from the motor shaft.


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## JeffHurl (Apr 22, 2021)

I'm guessing a small foreign object is up inside the gears that drive the train up inside one of trucks. I have a 1 year old N scale Kato SD70Ace that developed an issue similar to yours. I ended up removing the truck that wasn't turning, and found a really small piece of debris wedged in between two cogs of one of the gears. I had to use a straight pin to "un-wedge" what looked like a very small piece of clump foliage that got picked up when the train ran over it.

Kato SD40-2 truck maintenance

Not sure if your trucks are similar since these have 3 axles, and yours are 2 axle. And if you're are like these, don't fret... It's a lot simpler than he makes it sound.


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## Yoppeh7J-UPmp954 (Nov 23, 2014)

Take the shell off it. If the rear drive shaft is out of position you can see that as soon as you remove the shell. Turn the motor by putting your fingers on the flywheel to turn it.. Check to see if if both shafts turn. If they do look at the rear gear tower and make sure the worm gears are are turning and the top of the tower is down in the proper position for the worm gear to turn the gears in the tower.. Since all the diesels I have the top of the gear tower that holds the worm gear has arms that also keeps the trucks from falling out the bottom. If if it is turning the tower gears look for cracked gears slipping on the axles. That could be done before taking the shell off by moving the wheels on the truck to see if they turn. There should be a cover on the bottom of the truck too.


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## daveben (Jan 30, 2021)

Thanks everyone for all the great suggestions and input. I'm new at this and elected not to take the engine apart and screw it up more than it already is. I took it to the train repair shop a couple of days ago and am awaiting a call. Hopefully it's something simple. I need to figure out how to repair these things myself.


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## Old_Hobo (Feb 20, 2014)

Which means you will eventually have to take them apart, so….


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## JeffHurl (Apr 22, 2021)

Not a bad call at all, especially if you're not yet confident. Kato's are built really well, and with Diesels in general, it's usually a really straight forward task to remove the body shell from the locomotive. With Steamers, sometimes even removing the body shell can be more complex.

Sometimes a small problem will be more apparent and easier to diagnose simply by removing teh shell and having a look under the covers. Once you get to this point, you can decide to go further, or drop back and punt it to a pro.

Let us know what the shop finds.


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## pmcgurin (Sep 7, 2010)

When I was new to this, in the 1980s, I bought what the hobby shop had, Bachman steamers and F9 and Life-Like GP38s. I had trouble with them, and all have long since gone. I bought an N Scale magizine in the 1990s and gave it another try with Kato F3s by mail. I still have these and the Kato F7s and E8/9s. No issues with these. All still run as does the Kato GP40-2 and a couple of Atlas GP 40s and an Athearn F59PHI. I recommend you look up spookshow.net to get an assessment of anything you are considering buying. The assessments are sensible and will inform you about characteristics of locos and rolling stock as well as tidbits like DCC decoder installation. Lots of stuff tested and analyzed there.


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