William: Over time Aluminum cant take the constant un bolting and re-bolting that putting your tower up and down does. I had this same problem on my FTC tower. The main bolt that holds the upper tower to the lower legs got lots of use with me constantly folding my tower. What I did to fix the problem was a Heli-Coil.
Buy a Kit, It comes with Drill & Tap. You will drill out the Old threads larger and Re-tap New Larger threads and then Install a Heli-Coil. Its a set of Steel threads that become your new bolting surface. That way your bolting and un bolting into steel threads each time