Floor pan replacement

[CopperNick]

Yo, on the subject of the inner rocker panel, I ran into the same problem and ended up making mine from a flat strip of body metal, using a scrap piece of the original one as a template to locate and measure the bends and deflections. Be aware that if you go this way the total length of your basic panel is going to be around Six Feet!! because about 8 inches of it is invisible due to being located behind the front lower quarter panel. As for the strip that bridges the gap between the upper edge of the pan and the rocker panel seam, again, that is something that you get to make from raw body metal. To avoid having to do that, when you cut away the dead pan just cut as little as necessary to begin with. You can use the replacement pan as a template to determine where on the old one you have to cut. When you make your lines and go to do that cutting, don't cut on the line, leave some behind. Why? Having some excess material to work with means that you can sneak up to the final seam and get it as close and tight as possible; makes the mig or tig work a lot easier to perform. If you are planning on going with an overlap or lap joint, that extra becomes the shoulder or flange to which the pan gets attached. it gives you options including drilling holes in the pan and going with plug welds to make your seam.

As for the pan itself, OPGI has them, check their on line catalogue.


On versus Off. Advantages to both. On is faster and works better for small repairs where you can get at the damaged location easily. When I did my cabin floor pans i did one side at a time and did them with the cabin still on the frame. No way to lift the cabin at the time so hadda go with Plan X.

Off, if you have a rotisserie, is better for larger repairs but requires that the cabin be removed from the chassis and be completely taken apart to bare metal. Once you have the cabin gutted out to rust and corruption, the next thing to do is run crossbraces from everywhere to everywhere else, side to side, front to back, in the door pockets, and triangular as well. it should like a jungle Gym when you are done. And it is totally necessary to protect the cabin from twisting or folding when you lift it off the frame. For this, You Tube is your friend as it offers multiple videos on how best to run and locate those braces.

I never did take pictures of the first pan job but may do that for this pending one. Myabe.............................



Nick

 

[john87442]

Thanks for all the suggestions and information. On to watch some videos on this.

 

[Hurricane77]

OPGI has a couple different versions.

At least for the half pans:

This one welds to the inner flange

https://www.opgi.com/sheet-metal-body-panels/floor-pans/full-section-steel-floor-pans1/l241346.html

This one seems to have less of the trans tunnel and more of the outer sides.

https://www.opgi.com/sheet-metal-body-panels/floor-pans/floor-pan-full-section/floor-pan-1978-87-g-body-full-section-usa-99lm200.html

The second one is definitely not a factory reproduction and it doesn't have the joints in the same place. The picture there shows a continuous piece up towards the sill and up over the front body mounts, which is not how they were built. There's quite a bit of additional bracing and material in there in front around the body mount area and where the seat belts attach too. Would really be nice if someone would make this entire piece (or pieces) as a reproduction.

Here for example:

As CopperNick said, The inner rocker is easy. And you can actually buy that. But this entire section of sill will require fab work or a donor. I found a donor, but even it wasn't perfect and needs some remedial work. The side show above isn;t bad. The passenger side donor is much worse, but still better than what is in my car.

 

[john87442]

Thanks for that. I was looking at OPGI for replacements. The tunnel area doesn’t seem bad on my car just the outside flange area. But the seat brackets are bad. I’m a replace everything new mentality thinking to fix it all and know what you got, so I appreciate since I can’t buy these flanges new the knowledge and experience from everyone on what I’m up against. As soon as I get things stripped down that far I’ll post some pictures of ugly Ohio rot.

 

[pagrunt]

OPGI has a couple different versions.

At least for the half pans:

This one welds to the inner flange

https://www.opgi.com/sheet-metal-body-panels/floor-pans/full-section-steel-floor-pans1/l241346.html

This one seems to have less of the trans tunnel and more of the outer sides.

https://www.opgi.com/sheet-metal-body-panels/floor-pans/floor-pan-full-section/floor-pan-1978-87-g-body-full-section-usa-99lm200.html

The second one is definitely not a factory reproduction and it doesn't have the joints in the same place. The picture there shows a continuous piece up towards the sill and up over the front body mounts, which is not how they were built. There's quite a bit of additional bracing and material in there in front around the body mount area and where the seat belts attach too. Would really be nice if someone would make this entire piece (or pieces) as a reproduction.

Here for example:
View attachment 214437

As CopperNick said, The inner rocker is easy. And you can actually buy that. But this entire section of sill will require fab work or a donor. I found a donor, but even it wasn't perfect and needs some remedial work. The side show above isn;t bad. The passenger side donor is much worse, but still better than what is in my car.

That second one is closer to being a 2/4/wagon version with out the floor section as the first one is really a El Camino/Caballero floor section that will need the floor section trimmed to fit.

 

[CopperNick]

About the above ref 214437, That is what I used to do the floor replacement in my 85. The picture shows the driver's side, and is accurate. Mine did not come from OPGI, I used GoodMark instead., but same difference. All you get is the sheet metal pan itself. It does not come with the outboard/outer fold of metal that ends up against the rocker seam. And it is not a plug and play install.

For starters, if you use the whole pan, you have to cut away the existing component as far as the seam between the foot well and the upper fire wall; right behind the pedals. Then you have to remove the shoulder harness bolt and that can be fun? if you do not have the right Torx socket. Then you have to section out the rear half of the front seat mount in its entirety and set it aside. That can be done with a plug weld cutter and a drill or by carefully using a sawzall or similar to cut along the seam made by the bracket and the pan until just before it starts to rise up and over the tunnel and set the whole thing aside to be split apart later. If you have buckets, the same "harvesting" has to happen to the front pedestals for the front bucket seat legs, unless they are total junk in which case they are in the OPGI catalogue as stand-alone items. The ones I used were harvested from a donor hulk.

Be aware that donor parts often come with hidden rust inside them that has to be cleaned out and then the metal rust killed and painted out so that when they get installed and those compartments get sealed up, the condensation can't regrow the rust.

Once you get the pan sectioned out, you are going to discover that the transmission crossmember sits right there too. If you are just dropping the pan in from above and have no plans to visit it from below for any of your welding, then the T-member can pretty much be left alone. However, if you need to get at the panel in the vicinity of that member from below, it pretty much has to come out. This may prove to have to happen if you are going with replacing that sill extension shown above. Removing the old one plus whatever of the downslope of the metal is also compromised is likely to expose the t-member frame mount; a great opportunity to clean and rust kill and paint that area of the frame but that much more of a lot of mess and work added to your list to do. On the positive? side it also allows you to check out the T-mem mounting bolts and nuts and gives you the room to deal with them if they are nasty or rusted or rounded off.

The dirtiest and nastiest part of doing a whole pan side is that foot well. I ended up dropping out the steering mast completely. I then had to go below to gain access to that seam and remove the balance of the material that i had marked/scribed for that purpose to get it ready to receive the new metal. I also discovered that the leading edge of the foot well does not extend all the way out to meet with the inner bracing of the lower A pillar. Depends on what damage or rot you encounter in that area, how much fabricating you have to do to make the additional section needed to bridge the gap.

If you are only planning to do a half panel for just the front floor section on the driver's side, and the foot well portion of the old panel is still intact, then were it me, I would cut away only as much as would be necessary to get to clean metal on the existing panel and then fit/cut down/trim the incoming section so it exactly fits the hole you have created.

However, since you are asking about the sill and how to deal with it, as I said earlier, the OUTER rocker panel is available commercially; however, the INNER is a do it your self exercise and yes I wish someone did make them on an industrial basis but they would have to made in two sections that would have to be assembled either before or during the repairs as the inner, like I said, is somewhere between 5-6 feet long and that makes i oversize for shipping by box.

On my own project I am no where near popping that inner into place as I still have to carefully section away the front lower quarter panel to access the stump of the original inner and outer that probably are still in there. Most patches for that location were more by way of covers than structural elements and covering the problem was something you did when you wanted it to go away without having to invest in the time or money to do it right. They were cosmetic and under them, for the rust it was just business as usual.



Nick

 

[john87442]

Nick .. great explanation I really appreciate the insight and advice. I went ahead and bought the whole floor along with the seat brackets and inner and outer bracket. I’ll have to transfer the brackets for the center console but that’s fine. I’ll fab up the edges and hopefully document and post as good as you guys do. I’m going to do frame off one time so it’s gonna have to be done completely correct. I think it was years of the door seal leaking that totally rusted that floor out. Really going to have to research getting good seals…. But then again this ol gal isn’t gonna see any more bad weather.

 

[CopperNick]

Oh, yeah, you aren't done yet. There is actually one more brace that commended itself to me just a few minutes and that is the one found underneath the pan that connects the inner front bucket seat mounts to each other. it is a section of channel that bridges the driveshaft tunnel and which ends under each pedestal on the bottom side of things. When you start to remove the front floor pan ahead of the seat mounts be very careful or you can cut through it and then you either have to re-attach it at some point in the installation process or find a whole 'nother one and do a complete swap out/exchange.
Since you seem to be going the rotisserie route, once you get the cabin on it and spin the whole unit to 90 degrees from horizontal, you will spot that brace again. Again? Yeah again since you likely had to deal with it when you went to drop out the drive shaft during disassembly. That piece can also act as an adhoc safety loop should an "X" bearing fail and the drive shaft pop free.




Nick

 

[john87442]

Thanks, I did order a new brace that goes under the floor pan side to side, I decided just to make it all new so I know what I have. It wasn’t looking good after all these years of north east Ohio weather. Was watching a lot of videos today about welding in support cage before getting it on the rotisserie. Have a pretty solid understanding about how it is going to need supported. Last thing I want is to bend anything that shouldn’t be. Only other question is I see some people remove the glass first but some leave it in. If there’s no rot or reason to remove it i would rather leave it in. Opinions??

 

[CopperNick]

Good Question. Have you taken a peek at the cowl or roof where the edges of the windows sit? Water can accumulate under the trim and cause rot to occur. Probably wisest to remove the glass simply because any twist or torque that the body experiences while being turned can be transmitted to the window glass and cause it to crack. Taking them out, both front and back means that you don't end up having to shell out for new ones and gives you the opportunity to inspect and clean out the channels in which they sit to see if all is well. it also allows you to use one of those new two-part adhesives that do a great job of bonding the glass to the metal yet remain pliable to avoid damage to the glass and stay water tight.



Nick