We had a major repair for the back shops here on the Ballantyne Division...the J-Class stopped working. Now, I'm no expert on engine repair, but a magnifying glass soon confirmed that two small parts had become seperated and another part had bent as a result. Straighting out the bent thin metal was the easy part, but reconnecting the two other parts proved challanging. Finally, I got it back together and gave it a test run. At first, it would only run in the forward direction. In reverse, the wheels would almost make a complete revolution, then stop as if jammed. If slight pressure was placed on the engine, you could feel/hear a faint click and it would start moving backwards. Obviously, there's still something outta whack and not as it should be. After running it (at forward, full speed) it seemed to run without a hitch. And following the full speed test run, it would even run in reverse...only jamming up every once in while, and for a while, not at all. I'm sorry I can't name the parts in question. I have the exploded view of the Bachmann J-Class but don't know what the actual parts are called (in real life) to explain it better to you. Basically, the piston drive parts came apart and bent one of two thin metal guiding arms (but I'm sure that's not the right terms). What I noticed was this...there is a slight difference in how the main drive wheels are aligned and attached to the driving rods...are they supposed to match up? What I'm asking is, if one rod attaches at say the 7:00 position, should the matching wheel on the opposite side also be connected at the 7:00 position? Right now, if the left side drive rod attaches at the wheel at 7:00, the right side's are positioned at about 8:00...just a bit different. I was thinking when I reconnected the two small parts, I should have made sure the wheels were at the same point, or maybe that the pistion should have been at the same point. This is probably way to hard to follow, and I'm sorry I can't explain it better...I have very little steam engine knowledge, and none of my books here at home help. If anyone could direct me to a good steam website, maybe I can figure this out and fix the engine properly. But I'm open to everyone's ideas and expertise on how to fix this guy right!