This is why the front of our roofs rusts out!

[AKimmel]

This may be old news, but if anyone wonders why Dodges rust out in the front of the roof, it's because of a brace located just behind the roof skin. I just cut the front of my roof skin off to repair the rust beneath it, and man what a surprise. It's way worse than I thought. This is about the forth Dodge truck I've repaired, in the roof area, and this is the worst one internally. It only had some rust in the drip rail about 8 inches across. But, you can see from the pics that it rusted all the way through the frame work. Something I do to stop, or all least slow this problem way down is to rust proof the inside of the roof skin. The trick is to drill 3 holes on the inside behind the brace and through it. I drill one in the center and then one between the sunvisor hole and the center hole on each side the same distance from the edge as the sunvisor holes. My 87 had this done when it was new, but still rusted because they didn't drill through the brace also. This alows you to spray rust proofing between the roof skin and the brace and hopefully stop it from ever rusting through, if it hasn't all ready. If you have clearance lights you can spray through there. I use 3M Rust Fighter I, its basically military cosmoline. To tell if yours is rusting you can push on the outside of the roof skin along the front, and if you hear a crunch noise, then you've got rust. Mine had a good half pound of flakes sandwiched in there.

 

[sdstriper]

These are great pics, I have seen some bad ones too. I am refinishing one myself. The front fenders have a panel that traps moisture etc also. Good to remove strip down and treat the rust there also. I have been using Picklex 20 on the bare steel and Zero Rust where it's appropriate both really good products, then epoxy primer. On some of the B vans there was a service bulletin to fill the A-pillar with a low expanding foam for sound deadener, I am thinking of doing this in the roof and a-pillars. I'll treat up in there for rust at the same time! Thanks for the tip.

 

[91W350]

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I see that yours truck has the pitting in the front of the drip rail too. I followed a faint surface rust line from the drip rail back to the seam sealer. I kept digging at it and found this small area of rust. I treated it and then repaired the hole. The primer inside looks intact, so far. I am going to Rhino coat (Bedliner) the roof and drip rails. My truck does not have cab lights. Could have grown to be nasty if I had not caught it! I have other photos of the damage posted in my reader's rigs. Glen

 

[Headshot zod]

Where did you get the new drip rail? Or did you fab it up yourself?

 

[AKimmel]

I made it myself, the roof panel is 18GA cold rolled steel, and I repaired the drip rail with some 20GA.

 

[91W350]

That panel looks great, as these trucks develop more cancerous problems, you probably have an opportunity here! Glen

 

[MTownsend]

I think my 72 wrecker is developing a slight rust problem

 

[GIT-R-DONE]

Just discovered mine also had rusted through to the point that there is really nothing holding in the windshield on the top. Can you just cut the roof off and replace it at the seams or is it easier to just replace the cab?

 

[DVolk]

is why the front of our roofs rust out !

that must be te problem with my 92 it leeks around the window , on the top , if it was bigger id just spray the truck with bedliner and fix it



but i need a bigger truck

 

[DThibault]

I just changed a cab over to a southwest one for exactly the same thing. Sooner or later most of the cabs in New England look that way. One can buy just the roof panel from Dodge but I talked to some of the old body guys around here and they said it is next to impossible to put the thing on and line it up and not have yoiur windshield leak. I did see two different jobs where the guys cut the pillars, the inner and outer in different places, and then take the whole back of the cab down to the floor behind the seat where the natural body seam is and weld it back on. It sounds like a horrendous job but he said it wasn't bad and it came out looking real good. I chose to change the whole cab over and am very happy the way it came out. No leaks, no vibrations, no rust anywhere, almost new truck.

 

[Kiohio]

Sorry to dig up old thread but it had good info etc on it.

A question...

How can ones that are just starting to rust or aren't rusted at all prevent this?

Can you reach the bad spots by taking out the headliner and applying something like POR-15 and stop it from spreading/starting?



Thanks, KO

 

[Headshot zod]

I've been thinking about cutting a hole from inside the cab, getting all the rust out and loading up the area with a non-lead, metallic body filler.

 

[91W350]

Can you reach the bad spots by taking out the headliner and applying something like POR-15 and stop it from spreading/starting?

Nope, you cannot see it at all. There are a couple of small holes for the sun visors, but that is it. It has to be water or salt and water getting through that seam sealer between the roof rail and the top of the windshield frame. There is almost no room to look or work with the windshield gasket in place. Glen

 

[GIT-R-DONE]

If you have cab lights, pull them off one at a time and shoot oil or equivilant in there. You cant see the underside of the roof from the inside, its double walled, at least mine is.

 

[Philip]

If you have a cargo light on your cab. You can access between the cab sections threw there. But you need a long wand to reach that far forward to spray anything.

 

[KOG]

Foam filling the A pillars works on most vehicles. I've done all of our Caravans and it makes a noticeable difference. The CTD is another case. Can't hear any wind noise to begin with.

 

[Moab4x4]

Dang, I had the windshield and headliner out and didn't do this. Saw the thread too late. Oh well, living in the desert I expect I am OK as we only get 8" or so a year.



I am getting ready to repaint the cab. The factor sealer has a few cracks but no real indication of rust. Do I fill the cracks with primer, or should I go ahead and dig out all the seam sealer and replace it? With what??



TIA

Ken

 

[91W350]

Somebody down the road is going to hate me for this, but I cleaned out the bad areas, treated it with ant-rust, knocked everything I could find that was loose out and filled it with JB Weld. I figured if it ever needs replacement, I am going to cut the cab and door pillers and replace the roof and all at once. I still plan to have bedlinder put on everything from the seal over the top of the cab to the seam on the back. If it ever rusts out, I am going to have the top half of the cab replaced or find a truck that needs a drivetrain. I have a rust free 88 that the cab looks like the same thing. Glen

 

[jdurham]

Hey philip, did you do the work to your cab yet?

 

[Philip]

Jim I got side tracked with half the winter without a job.



Now I am trying to catch up on a few mechanical problems on the truck. After that I want to get my 47RH rebuilt. Then I'll start on the cab agin.



How you doing on the crew cab?