screw and nut 2 post car lift

[jacques@Mouton]

I did have the thought earlier, will this ramp have a safety nut?
It's not UK/EU based, and likely old enough where a backup system wasn't required.

It would be good to see some photos of how the nuts are arranged.

This is how they are arranged. Plastic/ nylon on top with brass underneath. They where in contact but may have been assembled incorrectly. The main nut has side movement so I think it's probably worn. They have 2 dowls between them that can't be seen in the picture but when main nut wears it pushes the dowls down and closes the gap.