Since most of the loads make the fit tighter, they are tight slip fit, but the forces aren't too strong to seperate it usually. Crashes do tend to loosen the joint
You could add a layer of tape to one side to get it tighter or the infamous BBQ skewer poked through both pieces, OR (shudder) a bit of glue. I liked being able to disassemble and put the plane in my scoot boot on the Electraglide.