Why won't my lead wheels lay flat on the track?

[BurtL]

Thanks for reading.  We have a White Christmas Express and it is giving us problems. It's a 4-6-0.  The front axle of the lead wheels will not lay flat on the track and the second axle ends up derailing itself as the truck flails about.  If I reach in and try to press the front axle to the track the front row of drive wheels wants to lift slightly.  I'm surprised at how much play there is in this front mechanism and my inclination was to try to fasten the lead wheel arm to the truck toward the back near the second axle to sort of pull up the back axle.  However, it seems like it needs that freedom to swing a little there in addition to the main pivot as the train moves in to the curve.  Any thoughts on what might have happened or how to remedy it would appreciated.

[trainman203]

Not familiar with that model but it's either missing a spring, needs, weight, or an element in the frame is bent.

And. Not knowing any details at all. It could be that the curve is too sharp for that engine.

[Len]

Back when my repair shop was open, I'd sometimes see something similar on Large Scale locos. What I'd generally find is one, or more, of four things:

1. The 4-wheel truck had been rotated 180 degrees from it's normal position.
2. The mounting arm between the truck and frame had become bent.
3. One, or both, mounting arm screws were over tightened.
4. On the truck end, the spacer on the lower side of the mounting arm was missing.

Here's a picture of the correct orientation of the truck and mounting arm:
https://www.bachmanntrains.com/home-usa/dwg/dwgs/LS_4-6-0_Metal_Gears.frame_&_wheels.pdf

Len

[BurtL]

Thank you so much for taking the time to consider and for supplying the exploded diagram.

If I look at the arm it does indeed have an upward bend just behind the mounting point to the truck and this would seem to have the result of canting up the front axle.  Hard for me to imagine what could have happened here to bend that pretty substantial arm.  I'm also missing the front wire guide on that arm.  Is this only a wire guide or does it have some sort of bumping or limiting action as well?  Both of the screws that mount this arm seem to have all of the washers and spacers but have a fair amount of 'play' in them.  I'm guessing that is normal to let it float a little. 

As a side question, what is the purpose of those wires?  They don't look like they serve as a part of the power take up but I don't see anything they connect to.

Merry Christmas,  Happy Holidays,  Burt

[Fred2179]

what is the purpose of those wires?  They don't look like they serve as a part of the power take up but I don't see anything they connect to.

(A picture is worth a thousand words?)
The front truck has two metal strips along the inside of the plastic truck frame which the axles pass through and transfer track power to those wires. They should pass into the chassis above the truck pivot area. Someone may have cut them?
The metal strips are separated by 2 nylon pieces pushed in from the underside. One has an arrow pointing forward (in case you might want to put it in the track the wrong way and cause a short circuit.)

If you want to stop the truck derailing, after you have bent the pivot arm so the truck has all 4 wheels on the track, take out the 2 nylon pieces from the underside so the metal strips are all loose. Remember which is forward and scratch and arrow somewhere on the plastic! Then apply some tape to the inside of one of the metal strips so they can't touch and create a short circuit.
With the nylon pieces out, the truck will become very loosely suspended and will stay on the track.