Broken captive subframe nut

[Boilermaker]

Paint shop broke one of the captive subframe nuts that holds the right engine mounting bracket to the frame. Here's a picture of the damage. They cut the bolt off at the head and lost the rest of the bolt and nut into the frame. I've been thru the frame rail as best i can with one of those magnets on the end of a flexible tube, and could not locate it.

What are my options for replacing the threads in the frame for that mounting bolt? Would a nutsert work or would i need to have a nut welded into the frame?

Also are there any tricks to getting stuff out of the frame?

[SilverXJ]

Your options aren't good for replacing it. I wouldn't worry about fishing the broken nut out. It might rattle for a bit then find its resting spot, at worse. How much torque to those bolts call for? A nutsert may work as long as they don't take too much torque. One option is to use a self tapping bolt, but I'm not sure that's much better than a nutsert. I'm not sure I would want to cut into the frame there to weld a nut in.