I have a rather high-torque brushed motor rebuilt & installed in my Turbo Optima, and it seems almost every time I hook up the battery, within a minute or so, the right-side wheels & nylon lock-nuts are zipping off. It doesn't seem to matter how much I tighten them, either.

The only thing that keeps the drive hexes from spinning is their contact with the axle shafts, where the shaft widens. The stock Optima/Turbo Optima never used hexes that lock on with set screws or pins, so the first time I saw those on eBay, I was intrigued. I've already purchased a set. But I still have to wonder why this is such an issue now, when it never was before?
P.S. I know the hexes go on only one way, the wider hole first.
