[Rowdy]

Proceed with caution if the nut flew off at you. Like Tom said it is likely the center bolt is broken. Take a couple of large C-clamps and try to clamp as much of the rear springs back together. Then see if you can take a punch and drive out what is left of the bolt. If you get it all out try to put a piece of allthread through the springs and a nut on ontop to help hold it all together. Rear springs are dangerous to work on. Rod