Try completely disassembling the truck tower and scrubbing everything with warm soapy water.  Rinse and set aside to dry.  Check gears for flashing and irregularities, and fix if necessary.  Reassemble and lightly lube.  I used to use Labelle, but am thinking of switching to Joe Fugate's method (synthetic tranny fluid).

Mike Lozensky

As most parts of the model are either delrin, brass, white metal, lead or some other formof plastic, rust is not really the issue. Oxydization yes but not to the point of consuming the model. 

As Mike suggests.  I would add take the model apart and take it into the bathroom. Grab an old tooth brush and some whitening tooth paste. The Whitening tooth paste is a tad more abrasive but it will clean out built up crud and oxidation giving you a nice bright finish providing better conductivity for any brass parts in the truck that route power to the decoder. Just keep the sink drain  plugged so no small parts make a brake to freedom down the drain on you. I have a cutout mesh screen I put in the drain to capture small parts that might get dropped.  The toothbrush and tooth paste will also polish the gears a tad, removing some buildup of dried grease and oil.  Once all is clean examine the parts for burs, roughness. The tolerances in the gearing are wide enough to get thru but any burs, roughness can still cause binds. 

If the parts count is high, take pictures or drawings. Keep the parts from one assembly together and try to keep them in the same orientation in an assembly if at all possible.  The parts will have some wear and seated, moving them around can casue binds that where not present before.

M2C

Marc Fournier, Quebec    

I'll give that a try today.  Its great having a resource like this where you get answers in mere hours! 

I've read that some folks use a product called Pearl Drops (dentures?) to polish their gears.  I guess it has a mild abrasive, and, as I understand it, they coat their gears with it, reassemble, and somehow run the trucks for awhile.  Later they disasemble again and thoroughly clean the assembly.  Supposedly this polishes the gears and mimics a year or two of wear, and hopefully smoother operation.  I've not tried it, but maybe I should with some of my Athearns that are stiff and jerky.  Anyone have any experience with doing this?

Mike Lozensky

Jeff Johnston recommends Pearl Drops in his book on assembling the MDC Shay loco kits. I followed his directions building mine and it seemed to help.  Pearl Drops is a semi liquid tooth paste. It has a very mild abrasive included in it to polish teeth and make them extra white. By adding them to gears you 'polish' off microscopic pieces of flash or wear down high spots. I'd recommend

don't run the gear train too much lest you wear away too much material and make the gears sloppy. Sorry - I can't give a good description of too much other than try it, clean em and see if they spin freely. If so stop. If not repeat the Pearl Drops application.

Be CERTAIN that ALL abrasive material is thoroughly cleaned from the gear boxes before putting the locos in operation.

FWIW

Charlie Comstock

btw. If the name Jeff Johnston seems familiar, it may be because Jeff provided the Gary Siegal ops videos to MRH that are on the MRH Theater page ...

Yep, I've done it and it works. If you want to quickly break in a stiff loco and get smoother performance, this is a sweet approach.

Couple this with a back EMF decoder and you'll get a really smooth-running loco.

Would a powdered cleanser such a AJAX work too to clean and work in the gears? I ended up using some powder on a tooth brush to clean up a box car that I over did with acrylic weathering, and it removed as much as I wanted without damaging the plastic or even the deacals underneath. I suppose if I worked hard at it I could have gotten to bare plastic, but it was very controllable.  

Steve  

but I couldn't find any pearl drops at the local store.  They look and move pretty well, so I'm just going to add a bit of auto tranny fluid and put it back together.  Thanks for your assistance. 

Remember, it's got to be Synthetic tranny fluid.

I've got the synthetic, thanks.