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jt50583 11-30-2004 08:30 PM

'69 mustang torque box replacement
I cut and pasted this q from the Intro forum.....hopefully I'm in the right place now......

I've checked all over the place in here and cannot find an answer for what I'm looking for. I am just beginning the rebuild of my '69 Mustang Mach 1 (M code). I've stripped it, had it acid dipped and have it installed in a rotisserie. From the inspection I've done (pic's are posted in my rebuild updates in this site) I need to replace both torque boxes, the front rail extensions, both complete floor pans, and a small section of the inside front frame rails. All these parts are interconnected and the best way that I can see to replace them is to remove them all start with the inside of the frame rail, fix that, then install one side floor pan, then the extension and lastly the torque box. The roof, pillars, firewall and rocker panels are all in good shape.
I would like to know if these components can be removed simultaneously? I plan on supporting the car at the shock towers to the floor and the rocker panels to the floor (while car is upside down) Do I need to do more? Do I need to consider a different order for parts replacement? Am I unjustifiably concerned? I'll figure this out one way or the other but am clearly open to input.
thanks in advance
John (jt50583)

julmer 11-30-2004 09:31 PM

I'm not familiar with that particular chassis but, in general, get all your replacement parts in hand and look at how they have to fit. That way, you can know what to cut and what you need to keep so half way into the rebuild, you won't catch yourself saying Oh @#%%^, I should have left that an inch longer.

oldred 12-01-2004 10:20 AM

jt-I have totally rebuilt two 64-1/2 mustangs in the past,one a nearly rust free car but the first one needed a lot in the way of panel and frame repair. If you have not bought your replacement parts yet I would suggest you be very careful when you do as I found out the hard way that all the parts suppliers do not sell the same quality parts. If you have already removed the frame pieces you could run into the same problem that I did with parts that only came close to fitting. I finally figured out that the reason I could not get anything to line up properly was due to a frame rail that was formed 1/8" too narrow and a fender apron that only closely resembled the original. These parts came from a major supplier(mustangs unlimited)and some were the so-called better quality parts(floor pans)which fit ok but had seat belt anchors and indents for the park brake cable brackets located in the wrong place. In fairness to mustangs unlimited they offered to take these parts back but in my opinion they should not sell junk like this in the first place. I ended up reordering from another supplier(NPD) that sells American designers brand American made parts and the quality difference was apparent when I opened the box, they fit! I am not trying to plug for any supplier as more than one sells these parts but one needs to ask before ordering. It is easy to see the alignment problems one can encounter when replacing frame and suspension parts and when the replacements don't fit it can be a nightmare that is why I try to pass on my experience with bad quality imports whenever I can.

jt50583 12-01-2004 08:35 PM

I appreciate both your comments regarding my problem. I found a place called Canadian Mustang Parts Store, however I know it is affiliated with an American counterpart. I don't know if it the same place you talk about but I will exercise some diligence before I order anything. (I've not order anything as yet)
I've spent the last few weeks researching a wide variety of issues that relate to the work ahead of me. I've purchased a new MIG welder, tracking down some 25/75 argon/CO2 gas and flow-meter. I bought myself a high quality spot weld cutter, which is worth every penny. I'm likely going to order the floor pans, torque box, frame rail extensions, rear quarter panels and a front fender prior to Christmas. If I buy at least $600 worth of parts, shipping is free. Canadian Mustang Parts Store is in Langley B.C. (thats in the coastal province adjacent to Alberta to the west for those of you not familiar with Canadian geography) I live quite far north so the shipping is a potentially large component of my costs.
I will ask for some references and follow up prior to ordering what I need.
I would still very much like to talk with someone who might understand how the load is carried throughout the Mustang body and to what extent I can rely on the remaining structure to carry the load after I remove these parts. I think I understand how the load is supposed to be carried when the car has it's full integrity, but like this it is clearly different and a bit more complex.
Again, thanks for the comments and keep em coming.....about this or any other aspect of the work facing me. JT

69 Stang Man 12-26-2004 11:18 PM

Be Careful!
You may want to go slow. If you can cut out and replace one piece at a time trying to keep the car structurely sound as you go. If you start hacking away at a uni-body it will start to flex as the supporting structure is cut. If you are going to have it mounted so you can spin it, don't forget to install door braces, or leave the doors on and closed as you cut the floor out to help keep the shape. You are taking on a big project, but it can be done right with a little skill and a lot of pre-planning. One place that helped me out a lot was...
Check this out, he did a total rip down and build up and had the smarts to photograph every step. If a picture is worth a thousand words, this guy's site could fill a couple books. My 69 is down to the bare shell and I'm about to do the boxes' and floor so I feel your pain bro. You won't have to rip out so much hair if you GO SLOW.

red65mustang 12-27-2004 09:59 AM

Your order is correct, frame, then floor boards and toeboards, then torque box.

Do one side at a time to keep the unibody straight.

Do ask for "American Designer" brand parts.

jt50583 12-27-2004 02:46 PM

drivers side floor complete
To: Stangman & red65 mustang

Thanks to both of you for the feedback, I'll check out that site stangman.

I have one floor complete, one floor extension support replaced, I've rebuilt the frame rail and welded in a new plate on the end of the rocker panel beam under where the torque box fits. The torque box doesn't quite fit the way I would like it too so am taking a break today and will tackle it tomorrow. suspect I need to make some minor modifications to it. the floor fit like a glove and the torque box is close so am happy with the supplier so far.

I braced the rocker panel with some square tubing to the floor which seem to hold things aligned while I worked on the floor and frame. Couldn't use my door, missing a hinge that I seem to get outbid on whenever they are available on ebay. Resisting buying a new one as they are expensive. Will post some new pictures this week.

red65mustang 12-27-2004 03:07 PM

I swear those torque boxes are "one size fits all" and maybe just change a part #.....

What I have found is the welds in a row along the rear bottem are very weak.
You can cut them loose with just a hack saw and bend the whole piece to fit better in a vise.
I use a couple of 1/4-20 bolts to hold the shape till everything is fitted then re-do the original welds.

And you took all the fun part out of the project using a spot weld cutter.......alot more fun to play "Texas Chain Saw Massacre" with a sawsall on the floors!

jt50583 12-28-2004 04:40 PM

torque box's

Well you're getting real time info here today. I just gave up on fitting the torque box. The top of the left box at the bend just in front of the spot welds is the problem. The bend needs to be closer to the top edge, it's too low. In order to get the
&$%*@ thing to fit i'm going to have to cut the spot welds free, rebend the end and reweld it. Otherwise all other dimensions appear to be good. There is simply no way it's going to fit as well as the original but I want it as close as possible.

I checked out that site you referenced on the '69 rebuild. He did a great job documenting his work. Not sure I agree with the way he did everything, but it's likely he wouldn't agree with what I'm doing either. I wouldn't have cut out both floors at the same time nor would I butt weld the joints on the quarter panels. A lap joint if done properly is not very obvious on the q panels unless you look for it. You can buy pneumatic crimpers for building the perfect lap joint and end up with a very strong weld. On the other hand there is something satisfying about knowing the joint is more difficult to detect as in the case of a well ground butt weld. I wish he had shown close ups of his finished weld as it might help me to change my mind on my approach.

I took some pictures today of what I've done on the drivers side floor, floor support and some material replacement in advance of the torque box installation. I'll try to get them posted this week. Let me know what you think and thanks for the reply once again.

red65mustang 12-28-2004 05:30 PM

coat the hell out of inside of the d-side torque box and caulk the top gaps to direct the dirt and water for best drainage along the bottem

The driver side doesn't fit because over the years the motor torque has bent everything as it got weaker.

It would take a good frame machine to twist everything back.

jt50583 01-03-2005 03:25 PM

taking the torque box apart

Taking the torque box apart was a good idea. In my project update you can see the box installed now. It fits pretty well and both joints inherent to the box are better now for it.

I'll take your advice on filling the gaps with a good sealer as well. The problem with the original set up is that there are holes that allow dirt and debris to fill up any cavity that is not plugged up. This material holds moisture which in the end is death to what ever it is exposed to. It's like holding a wet sponge on the material indefinitely. It doesn't take long in that kind of environment for rust through.

I've got some touch up to do on the floor interior but for the most part I'm done with this side. This week I'll work on the passenger side floor and torque box. It looks to be in better shape and I'm counting on less trouble. (That'll probably jinx er right there)

red65mustang 01-04-2005 03:18 AM

Glad it worked


On sealing it, you can't keep the crap out, especially when you use reverse

So only seal the vertical sides and top on the front facing the tire

Leave the bottem rear wide open so it dries quickly and road bumps shake some of the crap out

With the crap, and no salt, they should last another 20 years+

Once a year? bang on them with a 2 pound hammer to break the crap loose so it will shake out
Got GA clay? cut a 1" hole in the bottem rear so you can put a piece of hose on a pressure washer and blast it out

If you ever do another torque box install, spray the sh## out of it inside and out and the toe board with Duplicolor bedliner spray($7 Walmart/auto parts store,).
Also excellent for your new floors, sand with 80 grit and spray, tough as nails and absolutely water proof and if it ever does get scratched you just clean it and re-spray, it re-wets itself and bonds to the first layer.
Great product! try a can

Last thought, do seal the sh## out of the inside left where the toe board/torque box and floor and unibody all come together, "pack it" with caulk

rothpg 01-04-2005 12:31 PM

Hi guys,
I've been watching your posts with interest. I pulled up the carpet I installed 18 years ago on my 67 (on a solid floor), and found the floor mats are what was keeping my feet off the pavement. I'll be doing floor pans, toe boards and T-boxes as soon as I get space in the garage. Question: the coupes came only withthe d-side T-box. Is there any reason not to put both back in when I do this work?


jt50583 01-04-2005 06:50 PM

t-box's on p.side

I can't remember where I read it but I know I have read where people have put in a torque box on the passenger side of models that had only one. I think this was done in particular where the HP was increased as a means of dealing with any increase in torque commensurate with an engine upgrade.

I would certainly do it and if you can't find a ready made box I would make one. After dealing with mine, I don't think you would have much difficulty in making one or even fashioning something that would closely match their intent.

If I come across where I've read this I'll pass it on. I'd be surprised also if someone registered here hasn't done it already.


red65mustang 01-05-2005 02:27 AM

the only "don't do it" reason I can think of is if you want to keep a correctly restored car

it's a triangle, your adding (back) alot of strength to the subframe to the rockers connecting pieces that have been flexing and flexing and flexing....... for 40 years

Ford used one only to keep the car price down on 289 models, (65-66 have none) , it's a Falcon frame, designed for a lighter, less tq motor, needs help after 40 years

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