atlas rs11 truck gear problem

Model Railroader General Discussion (Model Railroader)
1

Hello all. I have a newer black box rs-11 that is having issues with one of the trucks. Seems like the gear is to small and not engaging the main center gear of the 3 gear system. so for instance power comes from the motor to the worm gear to the top gear of the 3 gear system. Here it seems go be smooth for half a rotation then bind up. If i spin the other wheel it free spins like it does not mesh with the middle white gear.

So I tore everyhting apart and took a look to see what was happening. With half the truck side frame off the gears seem to mesh nicely and not bind up. As soon as I put the other half on it starts to bind. I took it all apart again and used a triangle needle file to clean off any flash. Seemed at first that I fixed it and then Bang it is all bound up again. I added some grease and pushed it around on the wheels and it seemed ok after a while with no feeling of binding.

So then i put it back in the engine and run it around the track to test and it will not pull a couple box cars because it is binding but not only that the wheel set by the fuel tank seems to be missing the gears and free rolls and binds every now and then.

Any one have this happen? I have had a ton of atlas locos and they have all been butter smooth. I currently have 15 atlas engines(most of my current roster) and have never had issues . I am perplexed. Any help is appreciated. Other wise I am ripping all the gear out and it will be a dummy loco

mike

2

Compare the gears in the bad truck to the gears in the good truck. Seems highly unlikely, but one of the gears may be wrong.

Mark.

3

I’d study the gears very closely to see if one of the holes is off center.

Dave

4

Hello All,

I am not familiar with that particular loco.

That being said…

Do the side frames press on to pins on the truck?

I have a Bachmann 70-ton switcher that has press on side frames. The side frames also hold on the wheel wipers.

Between the side frames and the wiper is a small “dog-bone” shaped spacer. On one side of the problem truck the spacer was missing and the side frame was binding the wheels when fully pressed in.

I contacted Bachmann several times to find a replacement part to no avail.

The “dog-bone” spacer was replaced with four- -two on each pin- -Kadee #210 plastic washers.

This solved the problem.

Hope this helps.

5

Maybe check and make sure the worm gear shaft has the thrust washer in place. Here’s a view of the parts:

I have many Atlas locos too, and have not experienced this. I have had a simiar experience with an Athearn, and it turned out to be a missing thrust washer.

I mean as long as your taking it apart, study everything good.

Mike.

6

Been away for work so just getting back into solving this problem. I will give it a once over and see what I see. I would not think anything is missing as Atlas has always been a very good loco for me but it is possible. Updates to come.