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Hardened Oil Syndrome

You just bought a "new from old stock" locomotive. You were assured it was brand new and never used, yet when you put it on the track it doesn't work. If it has lights, they shine, but the thing doesn't move. Congratulations, it probably is new and unused.

Chances are your locomotive is suffering from Hardened Oil Syndrome (HOS). The lubricating formula Märklin used in Z locomotives through the early 90's had a tendency to solidify. Over the years it would take on the properties of glue, rendering the gears and other lubricated surfaces stiff or immovable. In many cases you'll find a liquified portion of the oil along with the solidified mass - as if the substance had separated. I've read the lubricant was vegetable oil based. Perhaps a chemist will come along and explain what the deal is.

In any event you're going to have to do some maintenance to get your locomotive moving. Here's a picture of a bad case of HOS. Click on it to blow it up.

There are basically two ways to deal with this - the right way and the other way. The right way would be to take everything apart, clean all the parts individually, re-assemble and re-lubricate with modern oils. The other way is free up the frozen gears, add some fresh oil and have the motor drive the gears forward and reverse until the fresh oil and friction dissolve the old oil and everything runs smoothly.

If you want to dissassemble the locomotive and clean the parts, more power to you. If you don't know how to do that or just don't want to, read on.

This job is relatively easy or just plain easy depending on the type of locomotive you're dealing with. If it has removable trucks then remove the shell, poke out the pins holding the trucks in, remove the trucks, put the pins back in to hold the main gear in place and roll the trucks back and forth over a flat surface until the wheels and gears move freely. Then take the pins out, put the trucks back in place and put the pins back in. Now, go here and wait until the people with connecting rod mechanisms catch up to you.

If you have a locomotive with an n-n-n configuration, such as a steam locomotive, then you'll want to do everything very carefully. If you let the gears or wheels fall out you'll be spending a fair amount of time getting the wipers back in place while you're aligning the connecting rods and getting the wipers back in place at the same time. If you have four hands and can solve Rubik's Cube blindfolded it won't too hard for you.

With the locomotive upside-down, remove the gear cover plate. If there are front or rear pilots try to keep them sitting in place when you remove the plate. They may fall off anyway but they aren't too hard to get back on - remember how they were oriented. There may be copper tensioners too, remember how they fit to the pilots. Chances are removing the gear cover will expose the couplers and springs. Try to leave them alone.

For each axle gently grasp the wheels between your thumb and forefinger and rock the axle just enough to loosen it but not enough to pull it out of the gear box - not even a millimeter. We don't want them to come free of the wipers (the copper strips between the wheels and the frame.) Having loosened each of the axles, with a blunt tweezers gently loosen each of the gears between the axles. Now to confirm the mechanism is free, touch the tip of a small bladed screwdriver to each gear and rotate the gear ever so slightly - just enough to see that each gear does indeed move. Now, gently press each gear down so the entire mechanism is flush inside the housing. Add some fresh oil (labelle 108) , maybe one distributed among all the gears, replace the gear cover (along with the pilots, couplers, springs, etc.) Remove the shell so we can see what's happening in the next step.

Whichever type of locomotive you have, you have it back together except the shell.

Now the fun/dangerous part. Put the locomotive on the track and give it full forward juice for an instant. Then full reverse for an instant. Did the motor react? With any luck you would have seen at least a little jerking motion. With a lot of luck it moved. Just keep doing this back and forth thing paying special attention to the motor to see that it's turning, even a tiny bit. If the motor isn't visible look carefully at the wheels for any movement. Feel around the motor every once in a while. It should get warm - don't let it get really hot. If the the motor or wheels move at all, then by keeping this up the locomotive will eventually run. Just keep maintain your patience and don't leave power applied when the motor isn't moving. When it finally breaks free, run it for several minutes in each direction and it should be fine. Put the shell back on.

If this technique doesn't work then you're going to have to do it the right way - or have someone do it for you.

Next time, after the seller says "it's brand new" you might want to ask them "but does it work?"

brian redman

Sat, Jan 28, 2006