Replacing a nut welded inside the frame

[L0jik]

I was taking off my rear bumper the other day, and when taking off the vertical bolts that go through the bumper and into the frame rails, one of them broke free and started spinning. So after a sawzol, dremmel, impact chisel, and the good old crow bow/hammer combo, I now have no way to put a bolt back into the one side of the frame rail to put the bumper back on.

There is a "drain" hole like 6 inches back from where the nut that broke off is located (which is how I fished it out once I had broken it off). How would I get a nut back in place there? Is it possible to just tack weld a new one in place through the drain hole?

I also saw on a different forum, someone recommended just welding a random bolt to the side of the nut, and fishing it in place, that way when you start to tighten the nut, it spins, the welded on bolt hits the side of the frame rail and allows you to tighten the bolt. Sounds a little bit ghetto, but are there other options that wont take a ton of work?

 

[freedom_in_4low]

The bolt welded sideways on the nut isn't the prettiest but the principle is common and already used elsewhere in the TJ where wrench access is difficult (upper control arm frame end nuts, axle end front track bar nut). It's usually called a flag nut.

I would feel perfectly fine with that option. Another would be a nutsert like what the transfer case skid bolts thread into.

 

[Infernicus]

I literally just had to do this as well.

I had some scrap laying around. I drilled a hole the correct size for the bolt. I had a buddy tack weld a nut in place. (It's not pretty, but it's solid for what it needs to do.)

I then used an angle grinder to make it the shape I needed to fit into the frame hole. It is hard to see, but I also bent it to sit more flush, inside and outside of the frame.

Here it is tucked into the frame. You can see the "flag" sticking out on the left of the circle.

 

[matkal]

I had some flag nuts made, I had the guy weld a piece of welding rod to it for a "handle" that could be bent to help fish the nut to where it's needed.

 

[L0jik]

I literally just had to do this as well.

That is the 100% exact same spot mine broke off. Which makes it convenient for knowing what it'll have to look like when I get around to making one. Thanks!

 

[PCO6]

I had some flag nuts made, I had the guy weld a piece of welding rod to it for a "handle" that could be bent to help fish the nut to where it's needed.

Flag nuts are a good way. Most shops that sell and install trailer hitches have a variety of them. A shop I've only been to a few times gave me as many as I needed for a project.

 

[Infernicus]

That is the 100% exact same spot mine broke off. Which makes it convenient for knowing what it'll have to look like when I get around to making one. Thanks!

No problem! I just kept putting it up to the frame and kept cutting away with an angle grinder until it fit. Once I had it mounted up I took a hammer and bent it the curve of the frame. I took it out and painted it, then reinstalled it.