I broke one of the four weld nuts that hold the bed to frame. I was able to loosen the bolt just enough before the nut broke loose so that I could fit a hacksaw blade between the rail and the frame mount to cut the bolt.Now i have a loose nut/bolt floating in the bed rail and no way to attach a new bolt. Is my only solution to cut a window in the side of the bed rail and put in a loose nut where the weld nut had been attached?

 

how about some pics, it will help...

 

I am guessing you are unable to remove the bed and weld another nut in for what ever reason .

Then your idea might be your best fix .

If you feel you really need that bolt .

 

Wyoming9, I do have the bed off. But the captive nut is, well, uh, captive. It is inside the frame rail with no access. During bed fabrication, I am guessing that the rail (u-channel in profile) with weld nuts already installed, is welded to the bottom of the bed, effectively sealing the weld nuts inside the channel.

 

If you have never done this type of fabrication I can see it might be confusing.

In essence what your doing is replacing the broken rusted nut with a new one

If you can weld just buy another weld nut most industrial suppliers sell them !!

Clean up maybe repair that section where the nut rusted and broke loose

Weld nuts are made with a wide flange on the top part of the nut to allow a good weld

I have done this same job quite often .

Living in the Northeast it is a given

 

Is there a need for the nut to be welded behind the u-channel? Will it interfere with installation if it's welded on the open side of the rail? If not, why not weld a new nut on the open side of the rail?

 

You could do that but remember the open side is up against the bed

You would need to open the side at that point you may as well just use a bolt and nut

 

I thought the top of the legs of the U-channel rail were welded to the underside of the bed thereby making the captive not inaccessible. So I was thinking of welding the nut to the underside of the U-Channel, which is the open side, that's why I was asking about interference. From what i've seen from pickup beds, there is normally a rubber strip to isolate the metal frame from the metal bed of the pickup so i assumed there must be some spacing/clearance between the ladder frame and the bed rail.

 

I would take a small rectangle steel plate that is smaller width then the hole. Drill a hole at one end for a smaller bolt size then the regular hole is. Make sure the length of the steel is longer then the captive channel. Thread the hole and then feed the thing up into the chenne through the holel and hold it there wih a magnet on the top or something. Then feed the new bolt (smaller diameter then stock) up into the plate for mounting. Then when it starts to turn inside the channel it will catch on the side cause it is longer then the channel is wide.