Rebuilding / Installing Hinge Pillar to Fender Seal

[Rich72C10]

Whenever my truck was worked on, at least two PO's before me, they left off the Hinge Pillar to Fender seals. This annoys me to no end. Some time back I got a pair from a forum member but they needed to be rebuilt. I didn't move forward because of the pain to get the fenders off! So to help motivate me I have started to rebuild them by getting a kit from GMC Pauls.

In case a reader is wondering, the metal brackets required for the seals are not reproduced - either you need to source used ones (like I did) or come up with a way to make them. Also, the sheet metal screws and spacers (shoulder washers) aren't listed on any of our truck part sites. The screws are somewhat easier to get but the right size spacers (shoulder washers) are a bit harder to substitute. The point of the spacers (shoulder washers) is to keep it from tearing the hole of the seal as you are tightening the hex screws down (or at least that is my guess). They aren't just a washers, the "shoulder" of the washer goes inside of the seal hole, basically the hex screw doesn't touch the seal at all. The shoulder can't be to deep or the seal won't fit against the cowl. Oh, it appears the reproduced seal holes from venders are slightly to small - so you'll need a hollow hole punch to enlarge them (somewhere around 7mm to 8mm punch). Though if you don't use spacers, then the hole is ample of size for the Hex head is 5/16 #10x1/2 sheet metal screws. Post #20 shows some pictures of the original screw/spacer and the ones I found for replacements.

I wouldn't say the fulfillment is 100%. The rubber cups seem a little lighter duty and the long bits are spongy feeling, where as the original long bits seems like some kind of heavy fiber-ish material.

1. Remove old seals from bracket, sand, and paint bracket.
2. Line up rubber cups on the long spongy bit and use a heavy stapler (I used 3/8 heavy staples).
3. Line up long bit spongy bit on bracket and drill a hole from bracket into long bit spongy bit.
4. Get the supplied super heavy staples from kit and start them through the long spongy bit into the bracket
5. Hammer them in!
6. Flip over the bracket and use whatever to push the stable legs over (I used a punch).
7. Use leather hole punch to widen holes for spacers, it appears the repos holes are punch to small.

Now I need to repeat and do the other bracket. Then I need to figure out how to get the fenders off but that likely won't happen until cooler weather and I can drive to my brother's for help.

I am also looking for the "sleeves" (shoulder washers) that are called out in the diagram, which with this spongy stuff I think will be important to have. Also hope to find some good sheet metal screws. The Hex head is 5/16 and are confirmed all to be #10x1/2. I also believe they are black oxide.

I'll update this post/reply with progress :-)

Edit:

Originally Posted by Rich72C10

Got a good match for screws and a so-so "spacer" off Ebay. The spacer is slightly bigger but it will work well enough.

Amazon Prime - pack of 25 for $9.16 shipped
18-8 Stainless Steel Sheet Metal Screw, Black Oxide Finish, Hex Washer Head, Hex Drive, Type AB, #10-16 Thread Size, 1/2" Length

Ebay - Pack of 10 for $10.81 shipped
Specbolt M6x18 Shoulder Washer Motorcycle Plastics Collar Bushings

[Rich72C10]

Ran out of photo attachments, I had one more.

Edit: Also it may be that when a truck has these you will also have Under Cowl Seals / Cowl End Seals

https://gmcpauls.com/rubber&ws1.htm
"1967-72 Truck, Blazer, Jimmy, Suburban, Panel Correct style & fitting hood to cowl foam end seals, these install on either end of the hood to cowl seal under cowl edge sealing entire cowl to cab area not covered by hood to cowl seal. Includes 2, 1 each for left and right side."

[Rich72C10]

So the screws for this thing!

On the Chevy diagram where it says: ".152/.156 DIA # Holes In Plenum/Hinge Pillar" does that mean a diameter between 0.152 to 0.156 inch hole? I found various data sheets that point to a 0.15x hole for a #10 sheet metal screw in 18 gauge sheet metal...

Basically fussing on the proper size 5/16 Hex Sheet Metal Screw....

[chewychevy67]

Here's what was factory on my truck. Screws are 1/2inch long. I'm having a guy 3d print me 20 washers like this because I can't find enough to do my truck as some were missing. My original seals have a more plastic feeling piece to cover the hinges and the repos I have are the same material as the main part.

[Rich72C10]

That answers one question, they are all 1/2 long. I have one original with that washer. Though my screw is really rusted so I don't trust the size and the washer is beat all to hell. I have a idea for those washers, if that works out I'll post about them.

Might you have one of those "what size is this screw" tools to see what # size it is?

Do you think 3D printed washer would hold up okay? Perhaps I could hit you up for some too, if my idea doesn't pan out :-)

The hinge covers, I agree the originals have a plastic feeling but that could be due to them being 50+ years old. The replacements are rubber and seem a bit thinner. I am sure the replacement material will be fine (at least for my life time).

[chewychevy67]

All the screws were the same

[Rich72C10]

Originally Posted by chewychevy67

All the screws were the same

Understood, looking for the official # size, #8, #9, #10? Sorry if I am being stupid and somehow I am missing that in your information

[chewychevy67]

I will have to check that out tomorrow. When I get the washers made ill post a picture of them. Not sure how long that will be.

[Rich72C10]

Originally Posted by chewychevy67

I will have to check that out tomorrow. When I get the washers made ill post a picture of them. Not sure how long that will be.

That's cool - it will be some weeks, if not months, before I'll get my fenders off. I should know late this week or early next week if my "spacer" hunt will work out.

My brother texted me when I shared my "project" that I needed help with. I think he wants to just take the hole front clip off - gee that seems extreme LOL.

Oh, thank you for helping - you're the best <3

[chewychevy67]

If I could find metal washers I would totally rather that as I use all original gm pieces that I can but nobody seems to have extras of these. I'm using my original seals again as well. They sit nicer against my cab as they have been in that shape for many years now.

[Rich72C10]

I am going to say this is a 5/16 Hex Lipped/Washer #10x1/2 Black Oxide Sheet Metal screw.

I finally found my bolt/screw gauge and my one original screw fits the #10 hole.

Loved to see what you come up for confirmation.

If so, I think I'll buy some of these off Amazon:
Small Parts 1008ABW188B 18-8 Stainless Steel Sheet Metal Screw, Black Oxide Finish, Hex Washer Head, Hex Drive, Type AB, #10-16 Thread Size, 1/2" Length (Pack of 25)

[Rich72C10]

I think I might have a problem? I was spying inside the fender / inner cowl crack when my door open and I think there is a lip on the inner cowl. I don't think that should be there - since the bracket won't be able to wrap around?

Thoughts? You should be able to see the lip I am talking about in my photo and I know from the PO about ~15 years ago the truck was "restored". I'm screwed - right?

[pjmoreland]

I don't have any experience installing fender seals, but that lip looks stock to me. I wonder if the seal sits directly in front of it.

I like your brother's idea to remove the entire front clip. It would save you from having to remove the grille.

[Rich72C10]

Thank's pjmoreland, I thought I saw you post something about the fender seals - I read so many post I clearly am confused but thank you for posting. Removing the clip does sound interesting and hard to believe that is "easier".

Hopefully I am just stressing/fussing so much that I am seeing "Boogeymen" when there are none!

[chewychevy67]

No I believe that is correct. That lip is supposed to be there

[Rich72C10]

Originally Posted by chewychevy67

No I believe that is correct. That lip is supposed to be there

Thanks! feeling better and better :-)

Edit
Found a photo of where the fender is off and member took photo of the door jam switch - I can clearly see the same lip. Now how this darn seal (bracket) gets around the lip is confusing the heck out of me. I suppose it will make better sense (I hope) when I have the fender/clip off and line it up. I hate mysteries!

I'll be taking photos that answers this question, perhaps some videos too, when I get to this install.

[mr.mud1]

hi Richard,i've looked again at your "lip picture" again, i think,unless i missing something,you're fine.that edge on the cowl looks the way it's supposed to look.i think the boogeyman got you?you looking at all this with your fenders still on,correct?when i look in my fenders now that everything is back together,you can't see much.i may have sent these to you already but here's some pictures of my truck apart,some pictures with the new seals i think and a couple with the old still in place.i think you're fine.

[Rich72C10]

Yep you did send those to me. I just don't see how the bracket fits flush around that lip to screw into the inner cowl on either side. Must be a optical illusion, compounded by me looking at my truck with the fenders on.

I even put my snake camera in there and can see two screws holes around the top hinge area and two screw holes below the bottom hinge area.

Basically I am looking into the door crack with the newly rebuilt seals in my hand and thinking how does it wrap around that lip I see and set correctly to be screwed down!

[mr.mud1]

you got this,they'll fit.no problem.

[Rich72C10]

Got a good match for screws and a so-so "spacer" off Ebay. The spacer is slightly bigger but it will work well enough.


Amazon Prime - pack of 25 for $9.16 shipped
18-8 Stainless Steel Sheet Metal Screw, Black Oxide Finish, Hex Washer Head, Hex Drive, Type AB, #10-16 Thread Size, 1/2" Length

Ebay - Pack of 10 for $10.81 shipped
Specbolt M6x18 Shoulder Washer Motorcycle Plastics Collar Bushings

• First photo the top screw/spacer are originals, then the bottom screw/spacer are parts listed above
• Second photo are some new ones and original staged on the seal.
• Third photo, there is one good hole on my original seals that I have and the "new" spacer sleeve fits snuggly - more or less like the original.

Personally, I think the hole stamping is a bit small on GMC Paul's Seal repos.

[mr.mud1]

Originally Posted by Rich72C10

Got a good match for screws and a so-so "spacer" off Ebay. The spacer is slightly bigger but it will work well enough.


Amazon Prime - pack of 25 for $9.16 shipped
18-8 Stainless Steel Sheet Metal Screw, Black Oxide Finish, Hex Washer Head, Hex Drive, Type AB, #10-16 Thread Size, 1/2" Length

Ebay - Pack of 10 for $10.81 shipped
Specbolt M6x18 Shoulder Washer Motorcycle Plastics Collar Bushings

The top screw/spacer in photo are originals
The bottom screw/spacer are parts listed above
Second photo are some new ones and original staged on the seal. Personally, I think the hole stamping is a bit small.

For the 3rd photo, there is one good hole on my original seals that I have and the "new" spacer sleeve fits snuggly - more or less like the original.

looking to me like you've got this figured out.

[Rich72C10]

Thanks Mr.Mud1! Perhaps @chewychevy67 will agree :-)

btw, while the Specbolt Shoulder Washer says "Plastics" in the description the washer isn't plastic - they are metal. I think whatever mounts on these washers on a motorcycle are plastic (I assume).

[chewychevy67]

Yes the hole on all the repos I bought are smaller than the shouldered washer but if you punch them out it is easily remedied. I did this to my repos. Also the 2 holes on My repo don't line up with the holes on the metal bracket.

[Rich72C10]

@chewychevy67 - funny, I was just thinking about punching them out. Thank you for mentioning that you did that!

Edit
Bought a 8-piece leather hole punch for 6 bucks at our newly opened Hobby Lobby, worked like a charm. My new sleeve (spacers) fit snuggly in the opened up holes.

[Rich72C10]

Job started! Great to see the holes existing. Now that I see how the seal lines up it all makes sense, more or less LOL

More to come once I have it mounted :-)