I couldn’t figure it out….but I fixed it.

[LIRR]

One of those frustrating head scratchers....

I have a trio of Atlas GPs. I have a double-ended staging yard that makes the visible point-to-point run a continuous loop. One lap is about 150 feet. I use them on a non-stop thru train, out from and back to staging, a couple of times per operating sequence (it may take me days or weeks to complete a sequence, operating whenever I can get in the train room). They always ran just fine. Then they started running like crap. Wheels were full of gunk. Cleaned the wheels using the old denatured-alcohol-on-the-paper-towel trick. Problem solved. But not really. In no time at all, wheels were full of gunk again. The wheels would gunk-up again after only a 2 or three runs. Over 2 dozen other locomotives would be fine after many more sequences. Cleaned all the track. No change. I happened to be reading a track cleaning post that noted often dirt is often picked up and spread around. So I looked at some freight car and noticed the metal wheels needed a good clean. Cleaned the wheels on over 200 cars, cleaned all the track again. Cleaned all the loco wheels. No change with these three. So I ordered and installed replacement wheel sets from Atlas.

They run like new now for as long as all the others before needing a cleaning.

Can’t figure out why only these 24 wheels got so dirty so fast…

[Freight Train]

I've found many different things that cause that gunk build up on wheels & track.  Things too look at are dust, air vent ducts, humidity and construction on your layout to name a few. Do you clean your track along with the wheels of your engines? Do you check for gunk build up on your cars? Plastic wheels tend to pick up gunk & spread it faster then metal ones. But running your trains frequently helps to keep wheels & rails clean. I had more problems with gunk living in the mid west due to humidity then I do living here in the southwest with a lack of it.....

[sizemore]

It sounds like the axle points and cups on the GP units need cleaning. Every so often (like the real 1:1) you should break down the loco trucks for maintenance. Pull the side frames off, pull the complete axles out. This should leave you the gear tower, 2 complete axles, 2 contact strips and the sideframe unit. I find neatly trimmed Q-tips in the shape of a point soaked in rubbing alcohol clean the contact strip cups well. Clean the wheels and axle points with a paper towel and alcohol. Use an airbrush at 20-30psi to blow the gunk out of the gears. Reassemble.

I have a few "lead-sled" GP-35's that need this treatment every so often, and the above really restores the performance.

HTH,
The S.