OK.
I hate to tell you, but that is not good.
The deeper question is why that flywheel "came loose."
As you know, the motor shaft is steel and it is not tapered. So for the flywheel to come loose in the first place, I can only think of a couple of reasons.....
1. Very very poor tolerances when the flywheel hole was drilled. Enough that it was BARELY snug when pressed on at the factory, but then just the warming of the motor was enough that it expanded and came loose.
The above seems a bit unlikely by itself......but...
2. The flywheel hit some obstruction. This could come from the shell or the frame. We already know that the solder blob was touching. Now we have an extra source of heat.
My guess is that 1 and 2 are at play together.
And here is the real problem now.... once the flywheel comes loose and the motor shaft spins in the hole, it ever-so-slightly reams out the hole. So the flywheel is never the same. I have see this happen when I have tried to "mill" and shape a flywheel without a lathe. Just place a flywheel on a wormshaft and chuck it in a motor tool. Cut spinning flywheel with a sharp file. Everything is fine until the flywheel gets hot from the cutting. Then it comes loose----and it is never the same.
So at a very bare minimum, the flywheels on this loco should be replaced.
It will have to be pretty much disassembled to rebuild the motors.
