Locomotive derailing from too much play in the truck axles?

I have had MANY Lionel steam locomotive models get their pick-up rollers "stuck" in Atlas switches. I changed out ALL the pick-up rollers on my Lionel steam locomotive models, and replaced them with the beautifully tapered pick-up rollers from Sunset/3rd Rail.

You could check to see that the rollers are centered on the frame between the drivers  and that the rollers do not excess lateral movement.  There have been a number of methods described here in the past about reducing wheel set lateral movement by inserting  various spacers around the axle between the driver and the frame. A snap rings (e rings) seem to have been favored. 

Hot Water, I searched around quite a bit on the web but couldn't find much of anything about how the Sunset/3rd Rail rollers are acquired.  Call and order directly from them?

David, good to hear that adding some spacers is legitimate. I cut up a cocktail straw and used it as a temporary spacer; the results were not perfect but pretty good, maybe better after experimenting with the amount of spacing.  I'll have to get some E-rings.

Thanks for the replies!

that axle play is normal and actually required to negotiate tighter curves. the disturbing part is when the axle shifts to one side the gear only makes contact at the very edge. add some blocking to the switch next to the center rail to stop the roller from dropping in.

Yes, order directly from Sunset/3rd Rail. Check their website on how/when to phone them, or eMail them.

It is clear from the picture that the pickup roller is in the wrong place.  It should be as close as possible to the powered axle, not the unpowered axle with all the end play.  Can you turn the pickup around so the roller is closer to the power axle?

I'd think the roller would be in between the powered wheels, and not at the end near those idlers.

John, the lateral movement would be minimized if the roller were below the axle for the powered wheels.  However, this is impossible, so moving the roller near the powered axle is about as good as can be done.  

I just checked my F3 and the roller is 5/8" ahead of the powered axle.

So, you're saying you turn the roller around?  That looks like it would certainly help.

Yes, turn it around and get it close to the powered axle.  The way it is now, I would think it would short against one of the outer rails going through a switch.

Apparently, that's exactly what's happening.

And, BTW, using a tapered roller will probably make the problem worse as the pickup assembly will drop down between the rails when the loco goes around a curve.

Personally, I'd be reluctant to change the roller direction/position, as if it is OK running on other track types (Down to O36 diameter.) then it should be fine on larger diameter curves. In addition, reversing the roller direction will shorten the distance between the rollers, and could cause other problems such as stalling when both rollers are on dead sections in crossovers or suchlike.

My choice would be to address the problems with the switches, as suggested above.

On that diesel, there is plenty of distance between the rollers, I tend to doubt the reversal would affect it much.  Of course, if it's a problem, you can always turn it back around.

Yea had a similar problem with a Lionel GP 9 and a K-line 072 switch track. The roller would drop down get stuck in the switch  derail and take half the train with it. Was a thread on this a while back. Someone on line here had said putting a tie from a piece of gar graves track in the space would stop the pickup from dropping down and getting stuck. Tried it on 2 K-line 072 turnouts and no more problem. Engine goes through like butter.