The Ford Barn

tinmann · 12-08-2012, 12:00 PM

I am considering welding threaded bungs to the underside of my '32 frame to make body bolt installation a little easier. It's been quite a while since I've disassembled one so I'm a little foggy on what the correct bolt and thread should be. I'm guessing the 8 or so body bolts per side that attach the body to the chassis should be 7/16" NF. I'm also guessing this would correct for the firewall to frame?? Any help would be appreciated.

Mart · 12-08-2012, 01:05 PM

A lot of the bolts are coach bolts with a square under the head, so you have to use a nut underneath. It sounds to me like you are trying to fix a problem that doesn't exist. From memory, most are 3/8". some are 5/16", and the two that pull the front of the cowl down over the firewall may be 7/16" (not sure on this)

I'd say just redo the whole thing using the stock bolts, it's not like you're taking the body on and off every other week, is it?

Mart.

34pickup · 12-08-2012, 01:08 PM

My repro 34 frame had long plates welded on the underside of the frame before it was boxed so that I could just drill and tap for holes anywhere I needed them. But the guy who built it drilled and tapped them for me and they were only 3/8 size which I thought looked too small. I redid them in 7/16 but used a coarse thread.

DavidG · 12-08-2012, 01:08 PM

The number of bolts depends on the body type. Originally, all of them are 3/8-24 carriage head bolts either 1" or 1 3/8" in length depending on location except the two at the forward edge of the cowl that go through the feet of the firewall (those are 7/16-20 x 2 1/4" hex head bolts) and the four inner bolts that attach the body to the inside of the running board brackets (which are 5/16-24 x 1 3/8" carriage head bolts).

If you have a late coupe, cabriolet, or roadster (or to ensure that your body does not develop cracks in the quarter and/or back panel sheet metal if you plan to drive your car on rough roads), the two rearmost fasteners were changed to 3/8-24 x 2 3/4" hex bolts with a drilled shank, 2 castle nuts, 4 flat washers, 2 cotter pins, and 2 springs similar to those used to fasten one side of the fuel tank to the frame as well as the radiator to the frame.

The firewall was attached to the frame with four 3/8-24 x 3/4" hex bolts (plus split lock washers and hex nuts).

tinmann · 12-08-2012, 05:37 PM

Gentlemen, thank you for your combined wealth of knowledge. I am now on the right track, I think.

DavidG · 12-08-2012, 11:42 PM

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Note that I added that the four 5/16 inner bolts were carriage head bolts.

12-08-2012, 12:00 PM	#1
tinmann Junior Member Join Date: May 2010 Location: Northern B.C., Canada Posts: 12	'32 body bolts?? I am considering welding threaded bungs to the underside of my '32 frame to make body bolt installation a little easier. It's been quite a while since I've disassembled one so I'm a little foggy on what the correct bolt and thread should be. I'm guessing the 8 or so body bolts per side that attach the body to the chassis should be 7/16" NF. I'm also guessing this would correct for the firewall to frame?? Any help would be appreciated. __________________ You can touch the coupe, just don't fondle the chicken.

12-08-2012, 01:05 PM	#2
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,750	Re: '32 body bolts?? A lot of the bolts are coach bolts with a square under the head, so you have to use a nut underneath. It sounds to me like you are trying to fix a problem that doesn't exist. From memory, most are 3/8". some are 5/16", and the two that pull the front of the cowl down over the firewall may be 7/16" (not sure on this) I'd say just redo the whole thing using the stock bolts, it's not like you're taking the body on and off every other week, is it? Mart.

12-08-2012, 01:08 PM	#3
34pickup Senior Member Join Date: May 2010 Location: Huntsville Al Posts: 1,526	Re: '32 body bolts?? My repro 34 frame had long plates welded on the underside of the frame before it was boxed so that I could just drill and tap for holes anywhere I needed them. But the guy who built it drilled and tapped them for me and they were only 3/8 size which I thought looked too small. I redid them in 7/16 but used a coarse thread. __________________ Matt 24:36-41

12-08-2012, 01:08 PM	#4
DavidG Senior Member Join Date: May 2010 Location: southeastern Michigan Posts: 10,101	Re: '32 body bolts?? The number of bolts depends on the body type. Originally, all of them are 3/8-24 carriage head bolts either 1" or 1 3/8" in length depending on location except the two at the forward edge of the cowl that go through the feet of the firewall (those are 7/16-20 x 2 1/4" hex head bolts) and the four inner bolts that attach the body to the inside of the running board brackets (which are 5/16-24 x 1 3/8" carriage head bolts). If you have a late coupe, cabriolet, or roadster (or to ensure that your body does not develop cracks in the quarter and/or back panel sheet metal if you plan to drive your car on rough roads), the two rearmost fasteners were changed to 3/8-24 x 2 3/4" hex bolts with a drilled shank, 2 castle nuts, 4 flat washers, 2 cotter pins, and 2 springs similar to those used to fasten one side of the fuel tank to the frame as well as the radiator to the frame. The firewall was attached to the frame with four 3/8-24 x 3/4" hex bolts (plus split lock washers and hex nuts). Last edited by DavidG; 12-08-2012 at 11:40 PM. Reason: clarification

12-08-2012, 05:37 PM	#5
tinmann Junior Member Join Date: May 2010 Location: Northern B.C., Canada Posts: 12	Re: '32 body bolts?? Gentlemen, thank you for your combined wealth of knowledge. I am now on the right track, I think. __________________ You can touch the coupe, just don't fondle the chicken.

12-08-2012, 11:42 PM	#6
DavidG Senior Member Join Date: May 2010 Location: southeastern Michigan Posts: 10,101	Re: '32 body bolts?? Sponsored Links (Register now to hide all advertisements) Note that I added that the four 5/16 inner bolts were carriage head bolts.