Frame Rail replacement

dviskoe

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Hello all, replacing frame rail on my '73 convert, and have a few questions for the group.

I'm replacing both rears, but I plan on doing them one at a time. Then the trunk floor, and both full floor plans.

the questions start with how to get the frame rails out.

this first pic is of the trunk floor, and there's a 'tray' where the convert motor sits on, but it creates a triangle of sheet metal enclosing in the frame rail. is there a way I can get to the spot welds without taking any of these other parts out as well ?

the second pic is of where i'm currently supporting the car ... on the frame rail. since this is SO rusty, where else can/should I try to support the car at ?

the inner rocker panel is so rusty as to not exist, do I replace it before or after the frame rails are in?

I'm a little worried about taking too many parts off at the same time and loosing the structure.

I've a few more too, like the rear of the frame rail ties into the trunk, and bumper supports into the tail panel. there's a piece that goes across that the tank straps slide into. But i cannot find that piece available anywhere, can i just make it ??

let me know what you guys think!

IMG_20130825_080649.jpg

IMG_20130825_080721.jpg

 
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Totalled

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So, the rockers are too rotten to support from the pinch weld?

 

marks73

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I supported mine at the rear torque boxes. That rear frame for the tank is available at NPD.

 

whitesoc

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Make sure you brace the car well before you remove everything. Remember with a convertible it needs extra bracing when you remove things as we don't have the extra structure a roof provides.

 

dviskoe

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so,

where do i brace, and with what i suppose is the important question,

and yes, the rockers are rusted to the point where I literally cannot even see where they are supposed to be .. ?!?

right now I've most of the vehicles weight on the front tires and 4x4 across the torque boxes, but since i'm replacing the torque boxes/frame rails, where's the next good spot for the weight of the read (not that there's much left ...

IMG_20130825_094945.jpg

 

marks73

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You'll need a rotissiery to do it proper and a lot of welded braces.

 

whitesoc

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I'm not an expert but I did read about a fellow that did a 65 Mustang convertible, here is a link to his website.

http://www.kevinsrodshop.com/floorrepair.html
He had a lot of holes to fill
He did, but you have to remember that with a convertible and a unibody the rockers are part of the integral strength of the car. A regular fastback or coupe won't twist as much as a vert will when you start to remove structure.

 
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[email protected]

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time to make at very stiff and strong jig and weld to what good spots you have. Only way to make sure what comes out is in same orientation as what went in (not maybe straight but the same) Good luck

 

Paul of MO

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time to make at very stiff and strong jig and weld to what good spots you have. Only way to make sure what comes out is in same orientation as what went in (not maybe straight but the same) Good luck
Don't cut anything until you have the car well jigged. It may also be a better option to put on a whole rear clip than try to piece this one back together. If you could at find a 71 - 73 convert parts car with a rear end that needed much less or no work you might be money ahead.

We "clipped" a 68 convert and it was surprisingly easy. We also took the opportunity to put in full subframe connectors. The car came out nice and was much stiffer than OEM.

The total cost of a no title, no engine, 68 convert shell with minor rust issues was less than the cost a set of quarters.

If you were closer I would give you the back half of a 73 vert that needs less work than yours but there are better ones availble and closer.

The key is the jig - you will end up with a few hundred dollars in square steel and a day or two measuring and welding.

Another option is to find a better car to start with and deligate yours to parts car status.

Good Luck - regardless you will have fun!

- Paul

 
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caspianwendell

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Someone started on mine before I got it. they replaced the inner rockers and cut the floor pans, so I have to jig mine to make sure it is right

 

dviskoe

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whitesoc, thanks for the link, that was very helpful. I believe that i'll do a door brace similar to what that guy had / did.

paul, thanks for the advice, i think i'll go start measuring now ...

:)

to replace the rockers, (if i'm going to, and it looks like i will need to ...) how much more will need to be tore open to get at where they go?

and the frame rails are still being stubborn, i cannot get to the section behind the rear firewall at all,

ideas ?

 
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droptop73

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Two words... CHASSIS TABLE

If you don't have something srtaight and flat to work from it'll be very difficult to get it right. Start with making the outer rocker level on both sides and equal height from side to side.

A friend of mine built a chassis table from 1/8" wall 4" square tube to build the chassis for his Dart. It needs to be level and square.

 

dviskoe

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ok, I've taken everyone's advice, and made a chassis table.

just got engine pulled and on the table today, tomorrow is clean/pressure wash and REALLY see what all I'll need to replace this winter.

(see local mustang thread here )

tomorrow, finish mounting to table square everything up and see what I need to replace this winter. so far I know floor panels and rockers. then to deal with the whole front-end.

question for the group on next steps,

on the inner and outer rockers, looks like they are 2 pieces, but I cannot find good reference pics, for a convertible (apparently they are different), how do they attach to each other, and how to tie in the convert. floor re-enforcements ?

Thanks!

 

PAPPY HAROLD

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X2 on the table. It appears you have skill, I would consider bracing the cowl to the 14 post at the top and even an X type brace from qtr post to qtr post. but I bet you already figured that.

GOOD LUCK

 

jrpav

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Not only does he have skill but it looks like he also has no fear! I predict a good chance for success. So how is this project coming along?

 

judge

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Just a note so you don't short cut this and regret it later. As some have stated, make sure you WELD in a brace from the windshield door post area to the rear quarter area-if you don't and the door area tweeks or gets out ofsquare-you won't know until you remount the doors;windows and weatherstripping and find out the windshield header I'd too far in or out. You could possibly move it with a body ram. But just brace it and forget it.

The rockers are three piece. Leave the outer in place while you install the inner. After I clear the path you can slide the inner rocker in through the rear wheel well. It takes a hand size hole that can be patched.

The convertible floor reinforcements just lap weld to the bottom of the frame rail and sandwich the floor in that area. Your major attachments are the front and rear torque boxes,the outer frame rail. Then the floor pan and then your floor reinforcements. Make sure you install the lower convertible cross member before welding the reinforcements in.

 
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