Body Mount/rail collapse

I have a 1971 CJ 5 and the brackets/mounts/rails on either side of the jeep where the body sits on the frame have collapsed. If you kneel down right at the drivers door and look underneath you can see it... same on the passenger side. Its a poor design in that they took a sheet of metal and made a rail or bracket for the weight of the body to sit on the frame. Years later one or both collapse. Anyway, my question is this... is it better to straighten that up and put in a metal spacer of some kind and weld it to the frame or maybe use a hard rubber spacer like the kind used for body mounts in general. Opinions? What have you done in this same situation?

 

The design is not as bad as you think, the problem was rust inside the hat channel weakening it and then it collapses.
Joe (project71-5)just finished his, here is a picture of his repair method.

 

I just replaced my tub bushings today to replace the wooden ones the PO used. On one side I had the same problem with the collapsed hat channel. I had some of the rubber bushing material that you use to make your own bushings with. I just cut that side a little longer and it just conformed into the collapsed portion. Here are a few pics. In the second one you can see how it re-shaped to fill the space.



Jim

 

used 1.5"x3/4" C channel to replace hat channel on driver side. mine also had the wood "lift" to help w/sagging tub, as far as i can tell it made the problem worse by stretching out the floor boards and holding water which made the tub rust faster.

 

Actually the "hat" channels that I'm referring to run perpindicular to the frame and there is no rust. I dont believe there was ever any wood in these channels it looks like they just collapsed from the weight over time. I could be wrong of course... wouldn't be the the first time. The pics that were sent above show a short channel that sits next to the frame running parallel to the frame. The one's in question for me are right on the frame and as I said they cross the frame. Metal spacers? or hard rubber? Would one be better than the other? Hmmmmm

 

Yep, there were signs of rotten oak inside my rotten steel hat sections. I'm now contemplating how to prevent water from sitting (and creating iron oxide) inside the rebuilt hat sections. My welding is certainly not waterproof and there are lots of spots where the patch welding has created more water entry points. My inclination now is to leave the holes as potential water exit points for the reinforcing channels. Thoughts???

 

Yup, my hat channels collapsed at the front two body mounts from years of rust. I dealt with it for 3 years but then I saw that the body was rubbing on the valve covers and bellhousing and wearing holes in them. Not to mention the fact that the body often flexed more than the suspension when on the trail. Oh yeah, I found pieces of oak still in my hat channels.

I fabbed up my own bracing with 1x2x1/8 tubing. The pic above shows what I did. The bracing is welded to the triangle firewall supports in the front and it has a vertical piece in the back that is welded to the rear floor riser. The outside brace is tacked along the tub sides and then welded to the rear riser in the same fashion as the other brace. Cross braces were then added at each body mount location.

I must say that the Jeep drives like a new Jeep and feels 100% more solid than before

 

I don't have pics but I took some angle iron 1/8inch thick by 1inch by 1inch and ran two pieces down where the old rusted hat was. I redid the whole front floor. I also used thicker metal for flooring.

 

I bought new channels from JC Whitney. 16 gauge and bigger than stock around 11.00 each @ 3' long. Where the body mounts I am welding in a piece of steel and drilling a 1" hole in the floor so when I mount the body I will no longer have floor and support colapse. I will post pics soon.

 

I sealed a few of mine with gobbs of black silicone then trimmed off the excess after it cured. Maybe not the preferred method but seemed like a good idear at the time.

 

Since I went to a frame-off process, I'm putting in new steel where needed. Here is a comparison between where I started and where I am now...

 

1stSGT....do you have a part number for JCWhitney for the channels. I am looking but can't find the channels online.

 

I wouldn't call it a bad design. It lasted 34 years didn't it? Yup the older CJ's had wood in the hat channel. (I thought a PO had stuffed it in there on my 67 LOL) Some also had a tube or spacer inside there so the bolt would not crush it when tightened. I don't know if the 71 had the wood or not. Classic Ent. is where I bought my replacment Hat C's from. Most of the pics you see here are towards the front. I think your talking about the body mount just to the aft of the pics posted.