A 3356 green horse car uncouple and vibrated (doors opened) when the unload button was pushed. However, it vibrated and doors opened when the uncouple button was pushed. Any suggestions on what is happening and how to fix it?
The 3356 horse car should only have one slide shoe. The other end of the coil is connected to the frame (ground). When you press uncouple, all of the 5th rails are energized, so the mechanism operates. When you press unload, two of the 5th rails should be energized, and two are connected to ground (assuming a good controller and proper wiring). Therefore, your horse car operating when you push uncouple is normal. Whether it works when you push unload will depend on whether the slide shoe is in contact with the hot rails or the ground rails.
In other words, there is nothing wrong with your car.
A 3461 log car uncoupled but did not dump logs. Any suggestions?
If it is not the same car mentioned above, the first thing I'd to is test the car by placing leads on the terminals. If that works, then I would place the leads on the little studs in the center of the two slide shoes.
There is a good chance that they just need cleaning.
I would start by cleaning away any muck with a QTip moistened with mineral spirits. Then a dry QTip to dry it off, followed by a little polishing with a fiberglass burnishing tool. Then another round of QTip / mineral spirits.
I would also check to make certain that the spring is pushing down on the shoe, and is springy.
I guess it's possible for the stud to be so worn, that it does not make contact with the extra rails, I really have not seen much of that situation.
You might also clean the tops of the extra rails on your UCS uncoupling track.
One last possibility: a bad solder joint. They happen.
I am using tubular tinplate track
Doesn't matter now, because you wrote that your uncoupling track is a UCS. I was wondering whether you had "O" or "027" track because the uncoupling tracks differ.