First, lets all agree athearn has let their QC slip. Next, not everyone cares if their loco wobbles side-to-side a little on start & at slow speeds. Still, easy fixes if you care! It seems the big motor and huge flywheels in this loco produce a lot of lateral torque. We can minimize that! Step 1: remove shell and open frame. You can loosen the screws and get the truck mounts out, or separate the frame halves and (with a bit of careful coaxing) leave all the "guts" in one side of the frame. Step 2: look at your truck mounts. Those brass contact strips that bend toward the trucks' contact posts? They suck. Those are supposed to stop side-lean by tension, but they are springy by nature. Remove them all, one by one (mark them with a sharpie on the top side outer edge so they back in the right way). While removed, re-bend them using flat tweezers to have a 20-30 degree downward slant. They all need to match closely! Step 3: grab some .010" Plastruct sheet styrene and a fresh blade. Make a shim that's slightly rectangular, about .9cm by 1.1cm. Cut to match the "c" shape below. I used white for visibility here, if you can use black that's better. Still hard to see after installation. Step 4: insert the wedges around the truck mount post between the truck and the mount (slip in from the back/motor side). Reinstall your brass contacts if you still have them all out. Use a slight bead of CA on a toothpick and run it along the back edge of the shim, away from the post hole, to secure it to the truck mount. Step 5: reassemble! With shell off, test for wobbles. All better? Now that the CA is dry, drop a .5mm head of Labelle gear oil on the face where the shim rests on the truck! The shim height should still allow enough movement for grades and superelevation, just a lot less room to wobble. Enjoy!
