I noticed yesterday that my son's 0-8-0 Lionel was running a bit rough. He's of course been running that switcher like a highball around an O-36 oval since he received it.
I pulled it and checked the drivers, wheels and contacts. I noticed that one rear driving wheel (the one with the traction tire) is loose on the axle, and given the great amount of slop between the drivers and the driver bolt into the wheel, it appears to be slightly "out of time" with the rest of the wheels on the driver. This looks like it is contributing to slippage and causing the loco to shake quite a bit at high speeds. At this point, only the driver/driver bolt is retaining the wheel on the axle. Removing that wheel's driver bolt, as the manual indicates to replace the traction tire, allows the wheel to be completely removed from the axle (it slides right off).
I'm going to give a shot at Lionel warranty repair since this is a relatively new engine, but was wondering if there was a low-hassle fix for this?
I'm surprised the axle isn't staked (or at least e-clipped) at the end to prevent the wheel from coming off. The other wheels appear to be press fit retained or something like that. The shimming jobs between the wheels and drivers seem pretty mediocre too, though as I understand it, some lateral axle movement is necessary to negotiate tight turns.
Any suggestions are welcome (besides telling the engineer to pour on the sand-haha).