Recently, someone gave me a box full of HO "scale" trains. In reality, they are mostly T-O-Y-S. One of the items is an old Marx Hudson. The motor does turn when you apply current to it, but it spins freely. The worm does not engage the idler gear. I did manage to figure out how to get the shell separated from the power chassis. I found a smoke unit with a gear attached to it(?). I lined up everything, applied current and the drivers spun. I then replaced the shell, applied current again. The drivers spun for a few minutes, then the motor spun freely and did not engage the idler gear. I went through this several times with the same result each time. Is this condition repairable or is it beyond repair and I should see if someone on FeePay will give me a few dollars for it for parts? If the condition can be remedied, does anyone know how to do it? Thank you in advance for any replies. Additional comments about what was in the box (those who want to avoid TL;dr can skip this): As I understand it, Marx manufactured these things from some time in the 1940s to some time in the mid-1960s. I am guessing that this one was manufactured after 1955, as it has X2F couplers on it. It appears that it once was part of a train set, as in the box was a Marx power pack, a yellow bay window caboose with minimal handrailing, a green(!) box car lettered for ATSFRD. I further suspect that a tank car with "Rocket fuel" or (something similar) on it was part of the set, although the tank car has no manufacturer's markings. The DC on the power pack no longer works, although that might be a problem with either the reversing switch or the rheostat, as the fatigue on the former plagues almost any DC power supplies to this day (even the good ones) and the latter plagued almost every train set DC power supply ever sold. I am in N scale, but girlfriend has expressed an interest in my building for her a small HO layout for her to run trains. The box had a TYCO trolley and an LL GP-38. I am guessing that it is a GP-38, although I am not too good on my second generation and later diesels. It has one truck powered and the other for pick up, so it is a train set T-O-Y as well. I did manage to get those to run, although they did not when I got the box home. Anachronisms are no problem for her, she just likes trains that "look pretty". She likes the CRI&P "Bankruptcy Blue" scheme, which is what is on the GP-38. Thank you in advance for your help.
It sounds like you have a cracked or loose gear if the motor is free to spin without the wheels turning. Usually the axle gear is to blame. How can the worm not engage the idler? Are they physically not touching? How is that even possible? If so, it sounds like you have broken motor mounts, or something isn't seated properly.
Either there's something loose or is being misaligned once the shell is put back on the chassis. Poke at the individual gears and see what moves. Run it without the shell for a few minutes and watch the mechanism. Watch until the free-spinning phenomenon occurs and concentrate on the worm gear and the idler gear. Note what moves and how it moves. Catch it in the act. Maybe the idler gear or some other one slides laterally enough to disengage the mechanism and interrupt the "mechanical circuit" between the motor and the wheels. Hope this helps.
