Body mounts and body bolts question

Well, a couple body bolts have made their getaway and are nowhere to be found. After looking at the underside of the tub and the hat channels, I cannot figure out how I am to replace the bolts.

Can anyone enlighten me on how the tub, hat channels and all are affixed to the mounts on the frame? I thought they must have dropped down through the hat channel but it doesn't seem to be that way.

 

Here they are on my '56 tub.

 

I guess my question should be clarified a little, did the head of the original bolt run from inside the hat channel down through the mount on the frame?

head of bolt in hat channel
washer
bottom edge of hat channel
threaded end of bolt
washer
nut

 

Mine were through the floorboard then the hat channel and to the frame. Looked like a carriage bolt.

 

CEEJAY5
You may want to check another recent thread out on the same topic. Here's my reply to that one if it helps:

"Not sure if its the same on a '73 but mine were frozen and they broke when I tried to get them out. The nuts were inside the hat channel (under the floor of the bed) I had to cut two holes in the bed, cut the old nuts out, weld patches back in, and then drilled a hole through the patch and installed new bolts (much like the body mounts under the front floor). If you're talking about the ones that go through the bottom of the 5" cross body channel they should have heads that you can get to, although they're not easy to get to (I also wound up replacing the 5" channel after finding some serious cancer on it). I had to cut most of my body mount bolts off with a grinder cutoff disc."

On mine the nut was in the hat channel...tacked to it (only on the two body mounts under the bed of the jeep), all the rest had bolt heads and nuts that were accessible. Bolt came up through the bottom. When the bolt broke off in the nut had no choice but to cut it out.

 

Dave,

That was a very helpful reply! I will have to take one more look at the body mount in question. It is the one that by the left rear wheel well.

 

Yep Tim, That's the one. The tricky part is measuring over into the floor of your bed and cutting the hole in just the right place to access the nut. If you do really well you might be able to just drill through the bed floor, through the old nut and then install a new bolt...and never have to do any welding. I wasn't that lucky...or good.