made a huge mistake buying thunder trucks.
been riding indy hollows for a while now, switched to thunders and the kingpin ends up falling right off after every two sessions. i ride my trucks super loose so thats probably why but its super fucking annoying having your truck just fall off your board. maybe i should just ride aces
Kingpin nuts fall off if you don't have them down far enough to engage thread.
Bushings can be purchased in softer durometers or even just leave off the bottom washer, or top washer too, if you insist on riding trucks that are almost non resistant in the bushing department.
Maybe even have a look at the Venture loose truck coversion kit, which has stock bushings but a lower head which really just means you can still have the nut nicely on but you get a lot more turn out of them.
I would say cutting down the top Thunder bushing as the cheapest option (free really) which would solve your nut issue, but I guess it is up to you to think and fix your problem, or just try something else like Ace which still could have the same issue if you can't get them loose enough on stock bushings so you leave the kingpin nut almost off there too.
What did you ride for bushings on Indy trucks?