I can't really tell from your images what's going on but it appears, by your description, that it's a drop bolt with the housing for the bolt attached to a wall and you want the bolt to slide down and turn in place to lock within the housing.

There's no bends happening here so do not check inherit bends. It's a translate Y rotate Y.

Before you adjust origins/centers you need to bake any scale adjustments you made, you can do this by spawning a prop from the group of the scaled object or exporting wavefront obj of the scaled object and reimporting. This will bake any scales as 100%

Once the scales are 100% default you can adjust the origins without things flying all over the place.

The inherit bends is probably causing the deformations.

So as I read it the parts are flying off (unbaked scale origin editing) and deforming (inherit bends)

Once these things are done the recommended parenting hierarchy would be parent the drop bolt housing to the wall and then parent the bolt to the housing. I would recommend setting limits on your translate and rotation relevant settings via dial settings menu, but that's not absolutely necessary, it just makes your dial settings and mechanical action less sloppy and exact to what they need to be for the action.