Windshield installation 1966-70 B body

[Kern Dog]

The older I get, the more I question things.
Sometimes when someone asks a question on a web forum like this one, some “helpful” member tells them consult the FSM/Factory Service Manual.
Yeah, sometimes that does help…. But not always.
The last few days, A buddy and I have struggled with installing a windshield in a 69 Coronet.

The owner has had the car for over 10 years. After it was painted, he had a shop install the same windshield that was in the car when he bought it. They did use a new gasket though. Within a few years, the upper passenger side flap/locking strip got torn and the tear spread to the point where he wanted to pull the glass to replace the whole gasket.
No problem, Rich…I’ve done this before…

The car was here two days. We tried and failed to get it done right.... and had to call in a pro.
What the heck went wrong?
I wish that I had taken pictures but we both were elbow deep in frustration and simply didn’t feel like documenting the damned thing.
We both have watched videos and also read different segments on web forums where people got the job done. Heck, I have replaced a few windshields in a few A bodies including front and rear glass in 2 Dusters. I have had the windshield out of my Charger twice.

To be fair, my car still leaks which I’ll get to in a moment….
The most glaring topic for me here is the matter of getting the glass in the car, the glass laying in right, the locking strip laying down and the trim fitting as it should.
The Coronet had rust in the cowl panel before it was painted. The shop made repairs but missed something that may have not seemed important to them at the time. The cowl is the bottom barrier of the gasket and glass. It stands to reason that for the glass and rubber to fit and seal right, you’d need some means to keep them from slipping down toward the hood.
This red cowl came from a 1966 Satellite parts car:

I saved the fender aprons, core support and frame rails to use if I ever crunch my cars enough to need replacement!

Lookie at the “fence/channel”…

You can see evidence of where there was some type of sealant.

@CoronetDarter

 

[dadsbee]

Next time send me an airline ticket..... ;o)

 

[Kern Dog]

Now look closer. It appears that the factory stamped the cowl panels and punched three holes and left a tab there to serve as a “stop” for the gasket/glass.

You can see a groove in the back side of the gasket.

It definitely keeps the gasket from slipping.

This Coronet didn’t have these tabs. I didn’t know what effect it might have on installation since the windshield did lay flat and nice before we went to work on it.
Following the instructions in the factory service manuals….

The text of both were either identical or almost so.

 

[dadsbee]

Yep and acts as a drain...

 

[Kern Dog]

Here is where it gets a bit stranger…

Read #s 2 and 3. Apply sealer in fence and glass groove portions of weatherstrip….apply sealer on cowl panel.
We did that. In fact, we had that great non hardening sealant you may have heard of…

For the record, Rich said he had no leaks before but admitted to not driving the car out in the rain. His car had no sealant in the gasket or anywhere in the metal frame of the opening.

Even with no tabs in the cowl, everything other than the torn corner fit and looked as good as any original car I’ve seen.
We thought that following the FSM would be smart but I think in this case, it made things worse. The sealant in the grooves made the glass not sit into the grooves deep enough, in a way making the outer dimensions of the glass and gasket seem larger (or the window opening smaller). The lower corners here…

…want to push and twist/roll the gasket out of position.

The FSM has a weird procedure…

See #6. Slide UPPER edge of glass in weatherstrip??
Yeah. Install from the top and work down. We tried that. It pushed the gasket out….probably because the cowl didn’t have the tabs in place but was that the only reason?
To be continued after a short break…

 

[Unkle Krusty]

Is the rubber one piece? Or is it two pieces?
Does the manual suggest putting the rubber, the gasket, on the vehicle, or on the glass.
Does the rubber have a slot to hold a piece of chrome trim?

 

[eldubb440]

 

[Kern Dog]

The gasket is a one piece design. I saved portions of the gasket to compare to the new gasket. What you’ve seen is just the lower section that sits in the cowl area.
We made sure the glass was clean. Rich bought suction cups, though I have installed windshields without them in the past. We had aerosol glass cleaner and a spray bottle with water and Dawn detergent. I have a pile of these sticks…

This was supposed to be a fairly simple gasket replacement. The glass was still nice. When he washed the car, he was always careful to avoid direct streams of water to the glass. Knowing that, I wonder how well his old gasket was actually sealing. That isn’t known.
In short, we tried twice to get the glass in and get the gasket to lie flat everywhere but we could not get there. We didn't even get to where we could start closing up the locking strip.
I know a guy....a dude I knew from Jr High in the 70s. He owns a local glass shop. He has been the only one I've had install glass in my newer cars. I did call him to install the windshield in my Charger many years ago but he was too busy to do it personally then so he sent another guy and yes...I had leaks. We went to his place to touch base and see if he could give it a try with this car. The soonest he could do it was NEXT Tuesday if the car were towed in.

Not good. I'll be busy then so we had to find another way. I found another local guy, he showed up today. Rich and I had the sealant all cleaned out of the window frame and gasket. THIS guy preferred to install the whole thing without sealant which has me curious....
The Coronet had no sealant when we pulled the glass out and as stated, Rich had no leaks with the car. Is it possible that the reproduction "Precision" windshield gaskets are designed to be used without sealant? Maybe a call to their company may clear that up.
The guy that installed the glass in my car years ago used no sealant and mine leaked. That is why I pulled it out to try installing it with sealant a few years ago. I've still had leaks that I suspected were from the wiper pivot seals so I replaced those and still I get leaks.
The arrows in the pictures below point to areas where water on the cowl drains to the inside of the cowl...

The two white arrows here point to areas that would drain to the inside of the car under the dash frame.

Closer view of the right side one...

In Rich's car with the dash frame in place, using a piece of bailing wire, I was able to slip through this hole and see the wire under the dash frame. IF water gets under the gasket, it can get through that hole. What is the fix for that? Some type of tape or RTV sealant over the hole?
I didn't have leaks in my car until I replaced the windshield and gasket. It never occurred to me that these cars had leaks in the windshield area until after mine was replaced. It seems to me that when new, this would be totally unacceptable. Jigsaw seems to have good fitment of the glass and trim.

I don't know if this is original but this car does not leak. Yeah, the rattiest car I own stays dry inside when I actually wash it. Life isn't fair.

 

[WileE]

I think it's a matter of luck. You can do any number until you hear that "bink" as I used to call it. Don't know how it is nowadays, but I'll say this, glass wasn't always "perfectly contoured".

 

[Kern Dog]

I measured the glass from Rich's car, it was .26". A spare new PPG windshield of mine....

....Measures .24".
A few years back when I broke my rear window, the new AMD replacement was also thinner.

For the rear window, it makes almost no difference since the glass sits on the butyl tape. With these windshields, they fit in a groove so the thinner they are, the looser the fit.
Today the man installed the glass without sealant but with Linseed oil.
Linseed oil - Wikipedia

This allowed the glass to glide right into place, the gasket flanges were easy to slip around the glass easily. Rich and I used spray glass cleaner and later water with detergent mixed in. For me, it sucked because it seemed to dry too fast, increasing the risk of tearing the flanges.
The man worked from the bottom UP which makes more sense to me than the factory method of going from the top DOWN.
I wonder how the assembly line workers were able to install windshields on the assembly line in a timely manner.

 

[Kern Dog]

Is the rubber one piece? Or is it two pieces?
Does the manual suggest putting the rubber, the gasket, on the vehicle, or on the glass.
Does the rubber have a slot to hold a piece of chrome trim?

To recap, yeah...the gasket is one piece but uniquely shaped. The Manual states to put sealant in the grooves then see 4-5-6:

The gasket goes in the window frame, the glass then goes into the gasket. The locking strip is mostly covered by the trim, though a little bit of the seam can be seen in some cases like this:

I think it's a matter of luck. You can do any number until you hear that "bink" as I used to call it. Don't know how it is nowadays, but I'll say this, glass wasn't always "perfectly contoured".

The installer today thought the glass was a tight fit, as if it were cut a little wider than it should be. The height seemed fine to him but the flaps on the A pillars were harder to fold over.
I want to learn from this and feel confident that I can do the next one myself.

 

[OKDart]

Interesting to read, I've got a "Precision" gasket and a windshield from a local supplier sitting in my shop right now waiting for my '70 Roadrunner. It might be ready to go in by the end Summer.
I've safely removed (original) front and rear windshields from a 1957 Plymouth by myself without damage to the gasket or glass (gaskets aren't available and glass is $$$$$$$). I will eventually put them back in.
I hired a guy to do my '68 Dart about 12-13 years ago, and wasn't impressed. I told him it needed sealant and he said he won't use it unless it leaks after installation. Well it leaked like the gasket wasn't even there, so he ended up using sealant and it stayed dry the rest of the time I owned the car.

BTW, That Coronet looks awesome! My '70 Charger was originally burnt orange, and may go back to that color.

 

[hunt2elk]

Getting windshields on these 1969 and older cars are always a major challenge to get leak free for me. I honestly don't know how that can be accomplished without using a sealer. 3M 08509 is what we use.

 

[Speedbird]

The factory manual is useless as you found out. You can do it yourself.
Bottom first, sides then top. The gaskets normally aren't the problem.
Sealant is necessary. Use lots on the bottom corners at the transition from cowl to A pillar. You found 8509??
As of a year or two ago there is NO comparable product.
I'm going over my emails with CL Lawrence and my testing of 777 and 7708 to refresh. (They weren't a lot of help and talked out of both sides of their mouth about it.)
777 "hardens" and 7708 remains tacky. I've used 7708 addition in the channel to assure non leaking covered with PTF tape prior to reveal molding installation.
Last I checked Steele Rubber listed 7708 which would work I guess. But again, it is NOT the same as 8509.

 

[Outlawd]

I put a new windshield in my 69 Coronet a couple years ago. I ended up calling a buddy that done my 68 GTX and has done many older gasketed windshields and we got it done but it wasn't easy, not even with a pro doing most of it. He told me every windshield is different no two are alike in how they install. Between the new glass being slightly off or the new gasket being slightly bigger or smaller and trying extra hard not to scratch the car and when that final corner finally pops in its a huge sigh of relief, there just isn't much room to play with. Hope I never have to do another one. Sealant was used in the cowl area only, no leaks that I know of but my cars don't get wet very often if at all.

 

[dadsbee]

 

[snakeoil24]

Guys tell me where to put sealant based on your best estimate

 

[snakeoil24]

Dad's been whats with all the tape?