#4 body mounting body to frame (rght rear)

[Kenneth M.]

The bolt that holds the body to frame has backed out (found it laying on the ground under the car pretty much below the exact position where positioned on car), I attemped to install bolt into place but it appears that the nut for the body is not in place? and obviously the bolt is just spinning, because the body backet is enclosed, I can't see if the nut broke loose from the body bracket (epoxy in place to the fiberglass) of if the nut is suppose to be loose.

Also, is there access to the body bracket to check on the nut from the back storage area under the carpet?

[Russ S.]

Re: #4 body mounting body to frame (rght rear)

Yes there is access to the nut which is held in place by a cage around it. Often times the nut or cage rusts to the point that it can spin. On coupe you will need to pull the carpet back a bit.

[Mike E.]

Re: #4 body mounting body to frame (rght rear)

Kenneth,

Here is a page of that section from my '65 AIM.




Here is a picture of the nut and cage from Paragon.




Mike

[Bill W.]

Re: #4 body mounting body to frame (rght rear)

there is a square nut under a cage . you will need to remove the cage and put a wrench or vice grip on the nut .

[Gene M.]

Re: #4 body mounting body to frame (rght rear)

Ken,
I've run into this issue more than not. I have an easy fix for you I do on most frame off's. Remove any of the remaining cage. Make a cardboard template of the fiberglass bottom of the pocket the cage sits in. Transfer pattern to 16 gage steel or stainless. Make sure pattern sits flat against fiberglass. Excess clearance around steel is ok. Mark the position of the hole and drill for clearance with 7/16 bolt. Weld a 7/16 stainless nut. Stainless so rust will allow removal at a later date. Steel at your own option. Screw in a new replacement 7/16 bolt and all is well.

[Dick W.]

Re: #4 body mounting body to frame (rght rear)

This all makes a good case for use of Never Seize on body bolts when you replace them. Easy to remove and minimal worries about breaking the nut loose from the cage.

[Richard M.]

Re: #4 body mounting body to frame (rght rear)

This is a '67 convertible but the concept is the same. As you can see in the AIM page above, the 2 rivets that hold the cage are installed before the underbody reinforcement, therefore it's impossible to replace the cage as original using rivets without removing the underbody reinforcement.

A process I use to replace this hardware is to drill out the remaining rivets and drill/tap the 2 rivet holes into the reinforcement for #10-24 machine screws. I use stainless steel. I cut the length of the screws to match the total thickness of the new cage, fg, and reinforcement along with flat and lock washers. IIRC it's about apx 3/8" or so. This will keep the ends of the screws flush with the bottom of the underbody reinforcement to remain unobstructed from the metal shims, and unnoticeable once the shims and body mount rubbers are installed. I then assemble the cage with a new square nut using the new SS screws. I use anti-seize on the screws and body mount bolts religiously. This'll help the next group of restorers when they do the subsequent 2nd, 3rd, and 4th restorations in the future.

All of this will probably be easier to accomplish on a coupe as you don't have to remove the decklid hinge towers to gain better access to the cage area on the convertible. However you may need a right angle drill to get in that area on a coupe to drill out the rivets.

As an aside, these cage nuts likely rust due to water intrusion from convertible decklid gutter blockage(as I've experienced), and coupe rear window glass seals that leak(my SWC did as well). Whatever you can do to keep water out will help prevent future rust in those areas.

Rich

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[Timothy B.]

Re: #4 body mounting body to frame (rght rear)

Richard,

I have not done a convertible but think the repair is easier than on a coupe because you can look from the outside while working on the nut plate attachment.

My back still hurts when I think about doing this on my 63 coupe, there is just no room, maybe with the rear glass out it's easier. I don't give up often but I ended up enlarging the nut plate rivet holes to where it sat flat over the two old rivets and used J&B weld to seal them down. Seems to work fine, I did not want more mess than fixing trying to drill and install screws but I like your method as that was my goal.

[Gene M.]

Re: #4 body mounting body to frame (rght rear)

Ken,
I've run into this issue more than not. I have an easy fix for you I do on most frame off's. Remove any of the remaining cage. Make a cardboard template of the fiberglass bottom of the pocket the cage sits in. Transfer pattern to 16 gage steel or stainless. Make sure pattern sits flat against fiberglass. Excess clearance around steel is ok. Mark the position of the hole and drill for clearance with 7/16 bolt. Weld a 7/16 stainless nut. Stainless so rust will allow removal at a later date. Steel at your own option. Screw in a new replacement 7/16 bolt and all is well.

I think you will find this is a lot easier and more sound as no cage to break away. Also just as easy coupe or convertible. My back is not threatened.

[Richard M.]

Re: #4 body mounting body to frame (rght rear)

Richard,

I have not done a convertible but think the repair is easier than on a coupe because you can look from the outside while working on the nut plate attachment.

My back still hurts when I think about doing this on my 63 coupe, there is just no room, maybe with the rear glass out it's easier. I don't give up often but I ended up enlarging the nut plate rivet holes to where it sat flat over the two old rivets and used J&B weld to seal them down. Seems to work fine, I did not want more mess than fixing trying to drill and install screws but I like your method as that was my goal.

True, since the decklid is off anyways.

Rich
p.s. my back always hurts doing this stuff.

[Gary F.]

Re: #4 body mounting body to frame (rght rear)

I replaced mine a couple of years ago due to the fact the rust built up in-between the mount and the body, which thus forced the rivets right out of the body. I did have the luxury of having the body upside down at the time. The old mounts were paper thin, & full of rust holes, and in my estimation, not worth saving. I bought a new set of mounts, but when fitted, they were too wide, so they got cut in half width wise, material removed, and re-welded. All the rivet holes line up, and they fit like a glove. The cage & nut has to go on first. I used correct style & size rivets, and it went together without any issues. Doing rivets works best with 2 guys. I had similar issues with rust getting behind and pulling the rivets out on my #1 body mounts.

[Steve L.]

Re: #4 body mounting body to frame (rght rear)

Just to add some expericience, on a 73 coupe, the only way to add rivets as per factory, is with a small air hammer with a tip shortened as small as possible with a rivet dome on the end- all custom by yours truely There is not enough room to swing a hammer.