I'm replacing the pan in my truck, and have found two layers on the pan where the floor meets the vertical or angled layer of the firewall. Is that normal, or has a patch been added in the past?

 

Looks like someone added a new floor in the past without removing the old. Don't forget about the cab mount in that area.

 

Also check the cowel drain under the fender./

 

Is that visible under the fender? What am I checking? To see if there is rust/rot?
Thanks.
So, just to summarize, there is supposed to only be one layer, right? And that layer lays against body mount, right?

After watching some vids, I realize that I thought there were two layers b/c the body mount extends quite a bit onto the horizontal surface of the floor. That is what the second layer is.

 

My has one layer stock, cab mount is under it. I have added a second layer, but not over the cab mount as that was undamaged by any rust. I added a third layer under the floor, is aluminum sheet, mounted with through bolts simply to shield the mostly sound stock floor from road dirt / water / slush / etc kicked up by the front tires. I coated my steel before.

Cowl drains.


I can reach into them laying on my back reaching up behind fender splash tub / shield, but is a stretch. Way easier if the fender is off. Might be able to see with a mirror just in front of the door, can even take kick panel vents loose if you have them, and get a small vac hose in from there.

 

TBear853: Thanks for the info and photos. You're always a help. I appreciate it.
Now I wait for the floor patch panel to get here, so in the meantime I'm shifting my focus to the passenger door. I have to pull the window out and change that metal piece at the bottom. I forgot what it is called, but mine in rusted through. I also need to cut out a small area of rust and splice in a patch.

 

There should only be one layer (other than in the cab mount area). Looks like (as another poster mentioned) someone welded in a new floor pan without removing the original pan in the past.

 

Pay attention to part # 112A70, looks like you are cutting alot of the cab mount support material/pieces away. You no not want the cab to settle. Jack/block it up in its originial height, befor you start cutting away anymore.

 

Lookc like you've got the kick panel opened up. You should be able to see a bunch of crud and the drain hole throuhg it.

 

Good point. I will do that. I will weld back in all that I removed.

I had to remove the bottom section to get to good, non-rusted metal. I also had to cut a piece out of the hinge post and will splice back in clean metal.

Tool recommendation needed. Does anyone have a good spot weld cutter?

Also, I was wondering about several rust spot that don't go all the way through, but yet are pitted. These are one the inside of the doors. Can I simply wire wheel clean and use some rust neutralizer, then coat with Por-15? Will that stop the rust, or do I need to cut and weld in a patch?

I'd hate to paint this thing only to have the rust pop through in a year or so.

 

On the LMC site, I notice that they have two types of front cab supports, oe style, and another. They offer no explanation except for the price: $67.90 for the oe, and $28 something for the other. The difference in the price makes me leery of the inexpensive and most likely cheap style.

 

Yes I changed some of your quote, and it made me laugh out loud. Just wanted you to be aware that your were getting into some STRUCTURAL parts.

 

I believe one is stamped from a single piece of sheetmetal. The OE style is stamped from two pieces and then welded together.

AMD supposedly sells the only one that has the hole for the parking brake cable through the mount, like the true OEM style. So if you are going to replace the drivers side, I would use the AMD ones so they both match. They are made in Taiwan, but they use heavier gauge metal than another American made version. I had to return an American made set because the two piece mount wasn’t welded together correctly and didn’t fit the existing floor pan. Even though I was replacing the floor pan, I didn’t want to change the contour of the new floor pan to meet a mount that might not line up with the frame later?

So far I’m very happy with the mounts I got from AMD and everything else I bought from Tabco. (The returned mounts came from another company)

The only thing I bought from LMC was the roof and drip rail patches. I wish I knew if someone else makes the drip rails, not that there is anything wrong with the ones I bought. They just don’t look exactly like the originals. The original one looks like they have a bit of a hem along the edge?

 

Thanks for the photos. Nice work. I just don't know if I could do such a nice job. I was thinking about doing a partial pan replacement that wouldn't require a level of skill that I don't have.
But I do need to cut out the bottom of the hinge post in the areas marked below.

I'm worried about keeping everything straight and fitting correctly.

 

Thanks for the kind words. I’ve never done anything like this before. So I’m going slow and taking ten times longer than it should probably be taking. I spent a lifetime working with my hands, so I guess that helps? I’m sure you can do just as good if not better. A professional would probably laugh at my work and pick it apart! That’s ok. I’m my own worst critic.

My floor pans aren’t rotted through, but the cab mounts had some rust pin holes through them. They were rusted pretty bad with no way to clean up the rust between them. That’s why I cut mine out. It seemed like it would be easier to just cut out the whole floor than trying to cut through, and match up all the floor ridges. I would think you would be better off cutting out the whole floor, or multiple floors.


I was lucky and that part of the inner rocker and “A” pillar wasn’t rotted. It seemed pretty solid, so I didn’t need to brace anything.

Now I have the cab corners, the back where it meets the floor, and part of the “B” pillar removed (I still have more to cut). It’s free floating, so that I have braced up. Cutting all the rot out should help me get in behind it and hammer and dolly out all the dents in the corner. Plus I have a bunch of slide hammer holes to fill up. I don’t remember a friend of mine doing all the slide hammer and bondo back when I cab swapped it around ‘91. Back then it was a rust free cab, but it sure wasn’t dent free!