Jim I’m sorry you’re disappointed. I watched the videos, I didn’t notice any obvious vibration. The loco actually seems to run very smoothly with good slow-speed control. This was my own experience with Legacy dual-motored diesels going all the way back to the first Heritage units with LionDrive and back-drivable gears.
With the Railsounds shut off there’s a fair amount of gear noise. Some of this could be caused by the chain snagging in the spur gears of the truck. If this were mine, I would just remove the chain. Fasttrack will certainly amplify whatever noise there is.
There are also several threads on the Forum about Lionel diesels being delivered with one or more wheelsets gauged too wide. This leads to excess side play and partial engagement of the spur gears on the outside of the truck block. If the gears aren’t fully engaged they can skip or make extra noise. If this is the cause of yours, you might be able to order a replacement axle, or even a whole truck block from Lionel, and hopefully get a good one.
IAIS is a cool railroad and they’re good looking units. Thanks for sharing, and good luck getting yours to 100%.
