I did not invent this technique. Last week Al Osterud, a veteran Marx collector of many decades, shared a technique for removing and installing Marx coupler springs without the skills and steady hand of a microsurgeon.
All you need is a piece of 1/8-inch K&S square tube, which resembles the tool Marx used to install them at the factory, and a toothpick or a straightened paper clip. Marx wouldn’t make anything that wasn’t easy to put together, which made its couplers so maddening to work on. Why was it easy in the factory and nearly impossible at home? With the right tools, it is indeed easy.
K&S tube is widely sold at craft and hobby shops, and even a lot of hardware stores have it. The small, old-fashioned kind of hardware stores, that is. I happened to have a 3-inch long piece of 1/8-inch aluminum square tube in my parts drawer so that’s what I use, but the type of metal doesn’t matter. You can use a round tube too, but the square one fits really nicely and gives you great control.
To remove a spring, simply slip the tube onto the spring from the back. The spring will release from its slot in the truck and its hole in the coupler and slip out easily. Pull the tube all the way forward, and the spring is out. No effort. Remove the spring from the tube if needed.
To install a spring, do the reverse. With the spring in the front of the tube, push the tube into the coupler from the front as far as it will go until the legs on the spring catch on the truck. Next, hook the lower, straight leg of the spring into the hole in the coupler with a toothpick or straightened paper clip. The square tube will hold the spring steady while you work on it. The top leg of the spring may just snap into its slot in the truck once you get the lower leg into place, but if it doesn’t, just nudge it into place with the toothpick or paper clip, then pull the tube out. The spring will stay in place. Work the coupler a couple of times to make sure it tilts and springs back properly, and your problem is solved.
The size of the tube fits perfectly into the position in the Marx truck where the spring goes and it holds the spring tight enough to make it easy to guide it into place. You can even use both hands if you need to. With this trick, installing or removing the spring is no harder than installing or removing the coupler.
I’ve always avoided removing Marx couplers as much as possible because I found the spring difficult to work with. I could get it back together, but with my shaky hands, it would take 15 minutes. Now that I can do it in a minute, I won’t worry about that anymore, and I’m sure there are at least a half dozen projects I’ve been putting off that I can do now, armed with this knowledge about how the trains were put together in the first place.