I have not been able to solve a problem with my SD 40-2’s, be it Kato or Athearn. On my broad and level curves, (they used to be banked until I tried to fix this problem) the lead trucks occasionally ride over the outside rails, and no I don’t speed. I have other 6 axle engines that work fine such as AC44’s. If the SD40’s are in the middle or end of a consist, they work fine. It is only the lead trucks that tend to want to ride over the outside rail. My curves are generous at about 36 inches. I also use NWSL wheel sets and all are properly gauged, including the track. So what’s the buzz, tell me what’s a happening.
I have a Proto 1000 set of FM Erie-Builts That do the same ting on one of my friends layouts, but not on mine. The reason was all in the track work were it had bumps at the top of grades and the tracks just weren’t smooth. Otherwise, I don’t really know what to tell you. If the wheels are in gauge and the track work is good, it should be fine. Hope I gave you some insight. Good luck…Jamie
I had this problem with an Athearns and I finally solved it by swapping the axels in the offending truck with each other.
Don’t know if this will help since your track work is already layed down. When I cut rails I make one pass with a file on the inner side of the rail to give it just a very slight bevel and make sure there is no burr on the metal. If your wheels are the right distance apart they should stay on track. What about pressure from the motor drive couplings? Do your trucks turn freely when motor power is being applied?
If you’re running Kadees, make sure the trip pin is at the correct height. If not, it will cause the problem you described.
Also check that the wheels are in guage…the newer Athearn Locos are notorious (sp) for the plastic axle that hold the metal wheels in place, to crack causing them to slip out of guage.
I used to have this problem when I used atlas set track on 9.5 inch radius curves and only my kato diesel loco derailed, while atlas locos were unaffected… Changing the set track to atlas flexitrack solved the problem. presumably the combination of track joiners and kato wheels made unhappy partners. maybe using flexitrack if you are using set track at the moment might help.
I have the same problem, but only when my SD40-2’s are going in reverse.I solved the problem by not sending then backwards & always coupled elephent style.
Gordon
Do they always derail at the same places? Could be kink(s) where track sections join that are just enough to reduce the radius at that one point. Depending on wheel play, some locos may complain while others track fine.
A kink will derail 3 axle trucks as the middle axle hits the kink and fights the lead axle. Often the derailment is not noticed until the loco arrives at the first turnout, sometimes the wheel will actually re-rail itself and you never notice the problem.
If it is a kink, rather than tear up and re-lay track, file the inside rail slightly at the kink to widen the gauge at that point. Then the middle axle won’t try to keep the truck going straight. Good luck!
Further to kinks:
A kink can also be caused by a slightly bent rail at the joiner. To test for a kink, place the lead truck on the suspect joint and try to rotate it by hand. There should still be a slight movement. If there is no give at all, this indicates that the flanges are tight against the rails at that point and the lead wheel will climb from the friction. A very slight filing can make all the difference.
I have not been able to solve a problem with my SD 40-2’s, be it Kato or Athearn. On my broad and level curves, (they used to be banked until I tried to fix this problem) the lead trucks occasionally ride over the outside rails, and no I don’t speed. I have other 6 axle engines that work fine such as AC44’s. If the SD40’s are in the middle or end of a consist, they work fine. It is only the lead trucks that tend to want to ride over the outside rail. My curves are generous at about 36 inches. I also use NWSL wheel sets and all are properly gauged, including the track. So what’s the buzz, tell me what’s a happening.
I have a Proto 1000 set of FM Erie-Builts That do the same ting on one of my friends layouts, but not on mine. The reason was all in the track work were it had bumps at the top of grades and the tracks just weren’t smooth. Otherwise, I don’t really know what to tell you. If the wheels are in gauge and the track work is good, it should be fine. Hope I gave you some insight. Good luck…Jamie
I had this problem with an Athearns and I finally solved it by swapping the axels in the offending truck with each other.
Don’t know if this will help since your track work is already layed down. When I cut rails I make one pass with a file on the inner side of the rail to give it just a very slight bevel and make sure there is no burr on the metal. If your wheels are the right distance apart they should stay on track. What about pressure from the motor drive couplings? Do your trucks turn freely when motor power is being applied?
If you’re running Kadees, make sure the trip pin is at the correct height. If not, it will cause the problem you described.
Also check that the wheels are in guage…the newer Athearn Locos are notorious (sp) for the plastic axle that hold the metal wheels in place, to crack causing them to slip out of guage.
I used to have this problem when I used atlas set track on 9.5 inch radius curves and only my kato diesel loco derailed, while atlas locos were unaffected… Changing the set track to atlas flexitrack solved the problem. presumably the combination of track joiners and kato wheels made unhappy partners. maybe using flexitrack if you are using set track at the moment might help.
I have the same problem, but only when my SD40-2’s are going in reverse.I solved the problem by not sending then backwards & always coupled elephent style.
Gordon
Do they always derail at the same places? Could be kink(s) where track sections join that are just enough to reduce the radius at that one point. Depending on wheel play, some locos may complain while others track fine.
A kink will derail 3 axle trucks as the middle axle hits the kink and fights the lead axle. Often the derailment is not noticed until the loco arrives at the first turnout, sometimes the wheel will actually re-rail itself and you never notice the problem.
If it is a kink, rather than tear up and re-lay track, file the inside rail slightly at the kink to widen the gauge at that point. Then the middle axle won’t try to keep the truck going straight. Good luck!
Further to kinks:
A kink can also be caused by a slightly bent rail at the joiner. To test for a kink, place the lead truck on the suspect joint and try to rotate it by hand. There should still be a slight movement. If there is no give at all, this indicates that the flanges are tight against the rails at that point and the lead wheel will climb from the friction. A very slight filing can make all the difference.