MTH 2-8-0 33-1038-1 pilots jumping rails

I had a similar problem with the trailing truck of a Mikado. The cause was the pivot on the truck moved off-center so the wheels would hit the turnout at an angle and derail. Check to make sure your pilot truck is centered on the pivot. Some 2-rail operators that had this kind of problem filled in the oval slot in favor of  centered hole to get rid of the problem. Filling the hole with a little epoxy, then drilling out a hole in the center would keep the wheels properly aligned.

I seem to recall some folks with similar problems saying that there needs to be a straight section next to a switch. I had a derailing problem with a new Berkshire and solved the problem by swapping out the pilot truck for an old post-war truck. I have a newer Pacific with an abortion of a pilot truck that will derail on a whim, that I have not corrected as yet.

FWIW, I had an MTH Mikado that was the 2-rail/3-rail switchable version.  Even though the wheels were not scale wheels, they had smaller flanges, doubtless to run on 2-rail track without issues.  It refused to go around either Fastrack or tubular track curves, even at O72, the front pilot would hop off about every third curve.  I tinkered for some time with it, then sold it.  It ran great on the club Atlas track, it just didn't like rounded profile track.

I wonder if it would be of value/possible just to remove the front pilot on this and make it an 0-8-0? I don't mind that it wouldn't be proto.. just want the stupid thing to run.

That is too bad on that Mikado GRJ, I really have no ambition to go to Atlas or anything else since I've got stacks of Lionel Tubular.

Midnight, it would figure that where these switches are, I don't have room for a straight.

AGHRMATT, I'll have to take a look at that and see if that makes a difference.

I had one like that when I was a boy. Watched it, monitored it, analyzed it and finally ripped that front truck off.

I have a Railking 2-8-8-2 that will run on O-31 track and 022 switches.  When I first put it on the track, the pilot truck derailed all the time.  I had to rework the pilot truck so it would stay on the rails in the vertical direction.  The original design would lift the wheels off of the track.  Needless to say, when that happened the pilot would derail.  After suitable modification, it did not derail any more.

If you have a set of calipers you can check the gauge of the pilot truck's wheels.

I got this from Steve at Ross Custom Switches:

Make sure the spring that holds them down is sufficiently stiff, and the back to back distance between the wheels (flanges) is not less than 1.025" and the distance between the place where the flanges meet the treads is not more than 1.245".

Dennis.

I've had good luck with a derailing 2-wheel pilot truck on both a K-Line mikado and on a Weaver 2-8-0.  In both cases I used one or two of those small wheel weights, used on "mag" wheels.  The weights stick on into place and add just enough weight to hold the truck down.  Derailments were eliminated.

Paul Fischer

Thank you all for the suggestions! I'm going to try adding more weight to it and see if that helps. If that doesn't work I'm probably going to reach out to MTH to see if they can suggest something.

Update on this. I took the front Pilot off and it works great. Hasn't gotten jammed up on any of the switches. I bought it new about two weeks ago, so I'll probably still reach out to MTH and see if I can get a replacement Pilot maybe.

While you have the pilot off it would be a good time to measure the wheels to see if they are out of spec.

Dennis

**Update**

After a while, I just got tired of it jumping the rails took the front pilot off, running it as an 0-8-0 essentially, it ran fine. I had it back and forth the (Somewhat)LHS that deals with MTH and they were pretty perplexed too, even took a stretch of track and switches with me and couldn't recreate/figure it out. My son loved it even without the pilot, so we just went with it.

Couple months went by, and I found myself out in the direction of the shop so I dropped it off again and just let them have it. They put the pilot back on, cleaned and lubed it and said that they couldn't get it to jump, even after runs around their layout and other peoples layouts it was fine. They said that it may just not be a good O-27 profile engine and that removing the pilot may just be the way to go.

I got home tonight and ran it, seemed to go ok until of course I hit a switch, and then a curve, jump jump, spark spark.

I was about to take off the pilot again when I started thinking about the play in that pilot. If looking straight on, you can really get a lot of twist/rotational/vertical movement on it. I put two small washers between the frame and the pilot, tightened down the mounting screw and ran it.

Perfect! No issues, no jumps, no sparks. Runs as it should, goes through turnouts just fine. The washers took almost all of the play out of the pilots so they no longer have very much vertical/wobble movement, but still move pretty freely horizontally.

Thought I would share an update on what worked for me, in case anyone else runs into a similar situation.

Will post pictures in the morning.

On my layout , one Ross turnout diverging rails directly connects to the second Ross stock rails, so when both are set to reverse, forms a continuous track curve.   My MTH Y6b pilot would go through OK, but the leading steam truck (correct my terminology if wrong) picked the second switch points and derailed.  I solved the problem by gluing a small piece of silver painted styrene, beveled at each end, before the points. In effect, the points are "hidden" behind the plastic piece so flanges can't pick the points.  The lead steam truck flange hits the plastic and pushes truck over so Y6b glides onto the points without picking.   Loco runs through turnouts from either direction without problems.

Crude, but works.

027.

Regardless of specs or other loco's behavior, tight curves will bring out tolerance issues before anything else. Lose the 027 curves/switches if at all possible - the 031, too, if you can. Your equipment will look and operate better in general, also.

I know - space is space and you've got what you've got, and we've all been there, but: it is usually better to have a better-functioning and better-looking layout even if you have a little less track.

This may not apply to you, but it's still good advice - and I didn't originate it. 

I've had derailment issues at various times, sometimes the fault of the track but also can be the fault of an engine.  And, if it's the engine, nine times out of ten it's the pilot truck.  You're right in limiting the vertical movement, but I've had occasions where a lateral movement of the pilot truck pivot allowed the truck to move and just line up the flange with a point or a frog on a switch.  Limiting that movement was a help.  But I find that one of the best "cures" for a derailing pilot truck is to add a bit of weight.  Perhaps just a half once or so.  The automotive industry uses lead weights with a sticky back to balance aluminum or mag wheels and rims.  You can usually get a strip of them from your local tire or service shop and these can stick unto relatively small surfaces on the pilot truck, sometimes adding enough weight to cure the problem.

I have a K-Line Mikado which was derailing it's pilot truck in several locations on the layout.  I first checked and increased the spring tension on the spring that provides some weight to the truck.  Helped, but didn't cure the problem.  So I stuck on two 1/4 oz. weights on the truck and tried it again.  About the time that I was testing it, my wife called me upstairs while the train was running.  Forgot all about it and when I went back down about three hours later, the train was still running.  I guess that I fixed it!

Paul Fischer