Hey guys,

I was talking to my dad the other day about my truck, and asked him about these plugs in the door jamb:



He said that was what companies like Ziebart did in the 70s and 80s to cars and trucks when they rust proofed them. So I took off my door panel, and sure enough, it looks like there's some sort of protective coating in there:



It seems like some sort of undercoating, and the passenger door that I put on from another truck doesn't have it. I guess I was just curious, does anyone else have this done?

My truck has spent it's life, until basically now, in Wisconsin. It was a mud truck for awhile before I had it too. I think that it's pretty darn clean for my area (except for older trucks that have been restored), so I think whoever did the rustproofing did a pretty good job.

 

The plug you have a picture of is a Stock Ford rubber plug. All the trucks have one in the same spot.

It is true that there were companys that undercoated these trucks, I just dont know much about them.

 

I think the door jamb plug is factory. The hole it covers is square, mine has them also. I bought a door from a parts truck and it had that spray coating on the inside of the door panel. I think it was more for limiting vibrations (take out the tin cup sound) because it's really only on the door skin and not as much down at the lower seam.

 

What about the bottom plug? My driver side door has a plug too, but the passenger one (which I replaced) does not. I was just thinking that it's rust proofed, because it's a very hard coating and the door that I got from another truck does not have it.

 

My truck had this done at some point in its life.

(which is probably what kept in such good shape being a Detroit truck and all.)

Below is from when we took it out of the paint booth. You will see the small holes running down the inside of the cab by the door frame. I have them on both sides of the truck and inside the hood etc (which are now plugged of course).

I think we counted close to 60 spots total where they made the holes and put it in.

 

here is a passenger side shot in case you are curious -- see the holes in the door.

 

ok last one, i promise

Here is another view of the holes for the rust proofing that you can see between the cab and door.

 

1/2" hole for rust proofing. We used to use a spot welder cutter. Guy at the dealership was undercoating the new 73 dent style, drilled through the rocker panel in the middle and shot his boots with undercoat.

 

Yes Ziebart uses alot smaller plug and its hard plastic not rubber, at least its that way on my Dodge.

 

Yea, mine needed 3/8" plugs.

 

Mine was Zeibarted. Plugs are yellow plastic. Worked ok, truck has been in Ohio it's whole life.