Hot Rods HELP !!!! 40 Ford Windshield Keeps Breaking

All states adopt DOT specification for auto gl***. Windshields must be AS-1. Specs minimun thickness laminate. All other gl*** can be AS-2, laminate or tempered. AS-3 is laminate or temered with darker tint.

 

Here's lots of photos I just took showing the "spacing" and windshield I installed in my 40 Ford back in 1988 using DRAKE rubber seals and the sealant that was available back then. I also included rear window photos. Do not use silicone as it's too thick and messy. It does a poor sealing job. You will regret it. Also, make sure your divider bar is properly installed and that there are no particles in the rubber channel that cause gl*** not to "seat" smoothly all the way around.. As I recall the P*** side goes in first to get the correct fit and overlap of the seal.Hope the photos help. Steering wheel is Crestliner.
Hot Rods - 1940 Ford Windshield Correct Installation - how to? | The H.A.M.B. (jalopyjournal.com)
and
Window Gl*** Installation Procedures (vanpeltsales.com)

 

There is a few things to try. First put a straight edge close to the windshield gasket at a right bridging the crack to see if it rocks anywhere along the crack. That may show its not flat. I would try to take a pattern off the opening windshield including flanges and transfer to a piece of 1/4" plexigl***. Use it to check the flatness. of the flanges. If it fails flatness then that is an answer. I got some 3/8" plexi from a gl*** shop that came out a pc of machinery that the plexi was damaged. The broken lexan I got was a fair size pc.. The broken machinery plexi is a shop waste so my local windshield and gl*** place gives it away. If its flat then put a piece of heavy cardboard or plywood in the good opening and trace the flange opening. Cut it out and flip it over and use it to the trouble side. One possibility is the gl*** was broken ions ago and a poorly cut pattern cut for the replacement that causes it to crack. Then the cracked wind shield used for a replacement pattern so its a legacy issue?
Bob Drake has gl*** patterns for a 40 Ford.
https://bobdrake.com/collections/wi...0-car-1940-47-pickup-windshield-gl***-pattern

 

I've seen '40 gl*** made flat across the bottom instead of the slight curve original Ford gl*** had. Another possible source of stress on the gl***.

 

To my eyes the post looks like it took a pretty serious lick right there note that the edge of the opening is squared up rather than rounded.

 

It appears that the interior windshield molding does not "fit" the contour of the opening.
You can see the edge of the molding in the areas of the lower green arrow.

 

That’s the inside edge of the door jamb you are seeing through the gl***. 40’s have a gl*** opening that is wider than the jambs are.

 

The door was actually fitting poorly in the body to the point where the gl*** was under bind when the door was closed. The door was gapped better and the problem was resolved.

 

True, all windshields must be safety gl***.

 

"The knee bone's connected to the leg bone......
The leg bone's connected to the hip bone......"
Glad to hear that you got it sorted out.

 

..Thanks for getting back to us with the resolution. Not everyone is that courteous.

 

Agreed. When I research problems/items I always hope to see a resolution. If not, are you really further ahead by reading?

 

Call this guy - Dustin (541) 579-8372 - he cuts all of Drake’s gl*** and get a shield from him. I got his number from Drake so tell him they told you to call. I have been down this road and there can be a great difference between stock and the .3rd party gl*** manufacturers. At least you will know you have the correct size gl*** and then start from there. Just my 2 cents……

 

....Looks like he got it sorted, Tom, but great information for the future. Thanks, I'm sure this will be a great help to others.

 

Tempered windshield is not something that you want, based on my knowledge of TEMPERED, it is used in side and rear gl*** units. It is used to shatter into little pieces when broken. Think about a rock hitting the windshield and all those little pieces hitting you at 50-60 mph, not good. The windshield is a laminated piece of gl*** and not tempered, like side and back gl***, so that when it breaks the laminate holds the gl*** and helps prevent it from cutting you with the slivers that would come off if the laminate did not hold it. Talk to a professional gl*** shop about it.

 

Dustin's business in Auto Gl***ics... I bought a complete set for my '40 two-many door and was very happy with the results. Had the kit in a week and everything fit perfectly.
https://autogl***ics.com/