# Gear wear



## cape cod Todd (Jan 3, 2008)

If an engine is moving along at say half throttle or faster and then the power is cut off either by a break in the track joint or power is cut to that track via a switch will it harm the gears of the engine. My thoughts are no because the engine can coast to slow to a stop but if the situation is reversed and the engine is at a standstill then comes to life and heads on its way can this damage the gears? I would think the sudden jolt of power of a throttle at half speed or better to the driveline could cause problems. I'm thinking about all the times that cunductivity is lost due to dirty wheels, dirty track, a failed rail joiner, or even a short wheelbased loco stopping on a frog etc that stops the train dead and as you walk over to it to tap it or give it a push along it takes off in a hurry. I can see this harming the gears either over time or maybe instantly depending on the engine. 
Any thoughts regarding this matter or am I just worrying too much?
Todd


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## Steve Stockham (Jan 2, 2008)

Depending upon the manufacturer, the answer is yes, probably yes or H*LL YES!! All gears are subject to wear. As has been posted here on MLS, Bachmann's gear problems with their Connie stemmed from "crappy plastic." LGB gears are more robust but they are offered as replacement parts too! Metal gearing is the most robust but it has issues of it's own as well. Slamming an engine into reverse is never a good idea! Small, intermittent stoppages shouldn't cause too much stress but again, they aren't helping matters either! Overloading an engine is a good way to accellerate gear failure and don't forget that improper lubrication will lead to gear failure far quicker than any intermittent stoppages!


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## East Broad Top (Dec 29, 2007)

I agree with Steve. By and large, the biggest enemy of gears is simply overloading them. Too long of a train, too steep of a grade, too tight of a curve--all things that introduce drag and cause the gears to really have to work to do the job of moving the train. Most cases of excessive wear that I've come across are at the worm/worm gear interface. The worm is typically brass or some other metal, while the worm gear is most commonly some kind of plastic. The softer material takes all the abuse, and will be the piece to wear out. (This is often exacerbated by the fact that the brass worms are machined, and sometimes have sharp edges that enjoy carving little bits of plastic away from the worm gear over time.) 

Having said that, the sudden stops and starts aren't necessarily _good_ for locomotive drives, but if the gears are robust enough, they'll be up to the task. The sudden shocks like that are more prone to cause split gears or shift the gear on the axle than to break or wear down teeth. 

Later, 

K


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## SE18 (Feb 21, 2008)

I think the hardest thing about some (but not all) gears is getting them out in order to replace them or clean them.


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## Greg Elmassian (Jan 3, 2008)

The amount of wear from sudden starts and stops can be excessive if you run automated systems. A lot depends on if the system is freewheeling. Stopping power will be much less wear than a sudden start at at attempted high speed. 

So if you are turning 12 volts on and off.. that's not great. See if you can get a "soft on" circuit. 

Wear is wear, caused by the force between the gear teeth, which is load, whether running or not. 

Maybe an expert like Barry will chime in here. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

If the gearing is properly designed, it will handle the shock loads of a sudden start or stop, or even a reverse. These don't produce much wear and if the shock doesn't actually break the gear, no harm, no foul. 

Running loads, especially with inadequate lubrication is what wears the gears the most. 

Old gears tend to shrink as they outgas over time. If the gear is pressed onto a shaft that is harder than the gear, the shaft will not compress and the gear will have to stretch to deal with the tendency to shrink. Eventually, this will cause a plastic gear to split. Then it will either make a clunking sound due to the teeth that are now too far apart, or the gear will slip on the axle, or both. 

- gws


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## aceinspp (Jan 2, 2008)

Key word properly designed. Most locos will not hold up to prolong sudden starts and stops as thy will eventually fail. Like years ago in HO . You need to ease into the stops and starts just like an auto with standard trany. To many burn outs and new clutch now needed. Later RJD


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## Cougar Rock Rail (Jan 2, 2008)

One nice thing about using decoders is they allow you to set the acceleration so if you do get a power off/on spike it will start up slowly when the power comes back. I'm not sure all decoders can be set to do this under DC as well, but the LGB onboard decoders and all Massoth decoders can do it. If you are running the EPL system, and/or want some insurance, you could always install an appropriate decoder. 
That being said, it's ridiculous how lightly some of the current drivelines are made...I think we all know which makes that applies to! With the loads some guys run with huge multi-unit trains we've really moved out of the realm of toys and into full blown industrial working machines. The problem is that most of the manufacturers don't want to build the drivelines to suit because of the cost of doing it right. 

Keith


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## BarrysBigTrains (Sep 4, 2008)

I have been in commercial situations, where a shuttle was being run. This type was simply turning the voltage/power off and on, tore up gears regularly, took the weights out which reduced the damage. The problem was there wasn't any control over how the voltage was being set. Being a 24/7 operation, there was no telling what was being done in the middle of the night. One clue: nothing survived, steam profile, desiels, or anything else. 

I am no longer there and haven't had a gear failure in more than ten years. My gearing is frankly over-engineered for the application and will remain that way. 

Barry - BBT


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## cape cod Todd (Jan 3, 2008)

Ah sage advice from all. It is just as I thought that sudden starts are worse for the drivetrain than the sudden stops. I haven't blown out anything yet but will continue to be careful by not overloading the engines. I do have some grades approaching 3% and some tight curves. 90% of my main line is on a grade either up or down. Seldom do I run a train over 4-5 cars long and most have metal wheels. Every bit helps right but in the long run anything that moves will wear out and eventually fail. 
The thing is to prolong that. 
Thanks


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## tomplatten (Sep 12, 2008)

Speaking of gears, I am not really happy with the longevity of the drive gear on my PIKO 0-6-0's. I am beginning to suspect the area of the frame that holds the drive gears in place. I think if the area that secures the drive gear axle wears too much it will allow the drive gear to move and the brass worm will tear it up. I have one loco that is on it third set of drive gears. I may try to order a new underframe!


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## rmcintir (Apr 24, 2009)

Posted By tomplatten on 21 Sep 2010 08:55 PM 
Speaking of gears, I am not really happy with the longevity of the drive gear on my PIKO 0-6-0's. I am beginning to suspect the area of the frame that holds the drive gears in place. I think if the area that secures the drive gear axle wears too much it will allow the drive gear to move and the brass worm will tear it up. I have one loco that is on it third set of drive gears. I may try to order a new underframe!

I really don't like the sound of that. Another member with a Piko 0-6-0 had a failure. Mine has been fine but it isn't a prime mover, I use it mostly as a demonstrator and as a helper loco at my buddy's layout on a section with a steep grade. I wonder if it should be lubricated differently?


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## Cougar Rock Rail (Jan 2, 2008)

Tom, do you have a lathe? If so, you could do something similar to the Digitoys solution for the LGB Ge4/4iii's: Machine down the axle in the area where it goes through the frame, and make some brass bushings to slide over the area you have machined down. The outside diameter of the bushing matches the housing, and then you would have a long term fix. 
Have a look here:

http://www.digitoys-systems.ch/cms/...;Itemid=27

If, on the other hand, the gears are failing due to poor design and not the housing wear, then that's another matter. 

Keith


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## chuck n (Jan 2, 2008)

Both of my layouts, one in Denver in the dark ages many years ago, and my present one in Virginia (had) have a reversing track where a train goes back and forth. My solution to jack rabbit starts and stops was to put a 10 ohm resister across an insulated rail joiner several feet from the section of track where the train was stopped because of a diode. The resistor slowed the train down by about half and then the diode stopped it until the polarity was reversed and the train started up slowly until it hit the resistor and came to full speed. In Denver I had this system on a cog railway on an incline and in Virginia it is on a spur that feeds my coaling tower. 



I have had to replace gears on my LGB moguls, but never on the engines that were on the reversing tracks. I haven't had any problems with the moguls since I took the added weight that I put in them, for better traction, out and started pulling shorter trains.


Chuck N


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