floor pan replacement
 

I believe that I'm going to have replace my floor pans in my 66 coupe. I don't know the extent of the repair as yet. My question is, since this is a unibody car, what bracing, etc. is required, if any, before cutting out the bad stuff. I probably will not be using a full floor pan replacement, but rather the individual panels. Thanks

RE: floor pan replacement
 

You first need to rip out your carpet and see exactly how much rust damage you have. Usually, one or both of the front pans need replacing, but not the tunnel or firewall. If you find that you only need to replace the pans, then take one out at a time and replace one at a time. That will insure you maintain the integrity of the unibody construction. If you can rent a plasma cutter, that is the easiest tool to use to get the old ones out. You will also need a welder and know how to use it. After you get the new pan spot welded in (don't make a solid seam because you will overheat the metal and warp it) then use seam sealer and POR 15 any rust that may still be visible like on the hump or firewall, then paint it. Good luck with it. This is one of the most common problems with the early mustangs because the cowl has leaked. Before you replace the pans, you may need to replace the cowls so that future damage can be curtailed.

RE: floor pan replacement
 

Thanks Soaring. I had a bad feeling this would happen, but whatever. My interior is almost removed anyway, so I might as well do the whole thing.

RE: floor pan replacement
 

What if you have to replace the whole floor? Is bracing required?

I'm getting ready to do the same thing but my whole pan needs to come out.

RE: floor pan replacement
 

In that case, I would suggest you remove the engine, transmission, etc. and put that Mustang on a Rotisserie. If you have that much rust damage in the floors, hump and firewall, you more than likely have extensive damage in the trunk area and rear wheel wells as well. If all that has to come out, you are going to need a rotisserie, otherwise that Mustang will fold up like an unbrella. Here is something you can ponder. Hopefully others who have been through, or are currently goiing through this process will chime in here.
http://www.mylittlegt.stangnet.com/custom2.html

RE: floor pan replacement
 

What Soaring said times eleventy billion... Dont cut the entire floor out with the drivetrain still in it. You are making it a headache to do it that way. Its much easier to do one side at a time and you dont need to pull the engine, but removing the trans and driveshaft makes more room. Working in sections will allow you to avoid trying to figure out where everything goes. If you pull the car completely apart cutting out the floors, firewall, frame rails, trunk, and rear end hump, you are going to have to know where everything goes. There is already someone dealing with that issue, one is enough. :)

Also working one area at a time will allow you to concentrate on that job. The trunk is a major repair of its own. The floor as a whole section is a huge job. A cowl repair will take longer than the floor will. Have you checked your cowl? pour some water down the cowl vent infront of the windshield, then see if the floor is wet. If it is, your cowl is rusted through and needs repaired. Leave the cowl like it is and the floor will be rusted out again in a year or two.

Doing the entire floor isnt needed unless there is major rust. If you want pics of major rust, just ask. A few of us are dealing with cars that most would scrap. You can still do it, but it adds work to the project. As long as it isnt a convertible it wont move around much if you pull all the heavy stuff from it. Additionally support the car with jackstands under the rear frame rails and just ahead of the torque box.

If you have never welded sheetmetal before you have a long way to go. Dont try it without some instruction, and just cutting and pasting makes for a nightmare that someone else has to fix. It isnt like bolting wheels on, you can mess up the alignment of the entire vehicle. The doors wont fit right, it could dog track, one wheel could be lower than the other, the fenders and hood could end up misaligned.. Just chopping stuff out when you can do it in sections is asking for a nightmare. If you want to do the entire floor, be prepared to gut the entire car.

That being said with caution, planning, and attention to detail you can replace the rusted parts relatively easily. But hey, at least you asked before hand what it takes. You get alot of credit for that! Most just start hackin away and then wonder what now? No offense to the guy who is dealing with the earlier issue.. He has time contraints and a way out, so its working for him. Plus he has a jig to make sure it isnt FUBAR...

RE: floor pan replacement
 

I am doing the same thing.. I came across this guys website and it was a little helpful to me because he also replaced the cowls.

http://personal.ecu.edu/boydd/tech/f...floorpans.html

This was the first pic i saw of a cowl replacement.My question to anyone is the cowl was set up to bring air into the stang so the inside could breath. But how about sealing them up will affect anything??:eek:

RE: floor pan replacement
 

Could be a problem for your heater and vents, and defrost would be impossible. If you have AC, that draws air through the passenger's side cowl. So, the only way you could seal them up would be to find a better way to draw in fresh air or never use the defroster/window defogger, heater, vents, and AC. Not a good idea, JMHO.

RE: floor pan replacement
 

Not sure I would recommend doing the cowl repair that way. I like the mustang monthly article version better, their way you remove the 120 or so spot welds holding the cowl on. You have to remove the windshield to do this however. You are still using the cowl reapir sections he used just not removing sections of the upper cowl.

RE: floor pan replacement
 

I've got the same problem with my 1969 convertible. I was doing some cleaning in the rear of the car and pulled the carpet back and got sorely dissapointed, as I found my drivers & passengers side floors to be rusted through!! So, my questions are: "Do I have to remove the seat boxes/ brackets that are welded to the original floorboards before I can replace the floorpans themselves? Then have to have them welded back in? Also, can anyone advise me on who I should get to perform such a task (body shop guys tend to be too expensive, or should I get someone who does welding work in general)? I'm from Mooresville, NC and there are alot of body guys/ welders in this area due to all the local raceteams in support of NASCAR. Thank you for any help/ advice in advance! Kyle