On my R/T, one of the front bumper bracket mounting nuts is broken off (welded to the inside of the frame). What would be the best way of repairing this? I assume I would need to cut the frame rail open, weld in a new nut and weld the rail closed again. Is there a better way?

I want to repair this soon so I can get it mounted on the rotisserie for winter.

Drill a hole in the frame, and do a plug weld tot he bracket - that is how the factory did them (except using spot welds).

Should work w/o a problem...

The pain is getting it in the right spot framerail & situated.

Use a bolt to hold it in while you are positioning it.

I don't quite understand what you mean by drill a hole. Do I drill a hole to get to where the nut was and weld in a new nut then seal up the hole?

I am also confused by the bracket reference. I have never seen a bumper bracket welded to the frame on any Challenger I have had.

Do you have any pics to explain what you mean?

The factory nuts are enclosed in a metal cage, or have wings (ears) on them and the cage or ear is welded to the frame rail.
I believe he is proposing that you drill a small hole in the area where the cage or ear should be and then weld thru the frame rail and attach the cage with that weld., then brush the weld flat and done. No structual damage to the frame.
The hard part will be positioning the nut for welding..,since it is probably laying somewhere in the frame rail ....
Another suggestion is to drill a hole with a hole saw from the opposite side of the frame rail and insert and weld from the inside, then use the slug and weld close the hole.

here's pic of my 70 challenger. MAybe it'll better able you to understand.

The Pink dots would the drilled holes in the rail. Then need to Plug weld thru holes onto the face of the bolt that surrounds the threaded opening. Then grind down. This area is hidden once bkts are in place. Holes approx. 1/4" or larger, depends on how larger the bolt surface is that in the frame. Tricky part is retrieving the bolt & aligning it back into place. Sure beats cutting a plate out of opposite end (which is visible) & welding/finishing it nicely.

Pic doesn't work.

I was gonna go in from the back side like stated above. I need go get out in the garage and take a better look at it again.

On mine i actually fished the nut out (bolt was broke off in it ) and then took a piece of 1/2 thick x 1 inch wide and maybe 1 inch long plate and tapped it then slid it down into the framerail, drilled two 1/4 holes through the frame rail and welded it. metal finished and was done