MTH Operating Car Derailment

I just purchased an MTH operating log dump car for my O layout, which uses Atlas track and turnouts. The car derails entering every turnout - the only piece of equipment to do so. Can anyone advise me what the likely problem is?

Thanks.

Check the gauge. An under-gauge wheelset will pick the switch points. I have found MTH cars with this problem. If a wheel is loose on the axle, remove it, upset the axle splines (just a little), and force the wheel back on.

rbr,

Your Atlas switches came with a plastic beveled insert to place before the frog to prevent the sliding “shoes” on operating cars from catching in the frog. Atlas switches are bad about this.

Did you install those pieces?

Also check the operating control rail sliding “shoes” on the bottom of the car’s trucks to make sure they are not hanging lower than just below the tops of the 3 rails. The shoes are also beveled to “help” them over cross tracks and switches. Regardless, the Atlas switches need the insert even if the shoes are in their correct position.

Regards,
Roy

thanks both. I will check the wheels, because the plastic insert doesn’t solve the entire problem, particularly when the car enters the curved turnout, at which point the rear truck seems to grab and then derails.

check the inner and outer diameter of the car and the switch-i have had problems with the inner diameter on engines and cars being to narrow-i spread the wheels outward and problem solved-i have gargraves turnouts

thanks