66 glass identification

[Dan M.]

I have what I believe is an original windshield. The markings look correct. The tint looks correct. The date code is "LA" which I believe indicates a March date. I believe my car was built around April 20th, 1966 based on the vin (19467 6S119767), so the date code on the windshield looks correct. I notice at the bottom of the marking it indicates "M4" but I am unclear what this means exactly. I also have 3 wiper blade scratches on the passenger side which I highly doubt will be able to be completely polished out. The glass is otherwise very good with no other imperfections. The scratches dont really bother me and my question is related to what the judges might think if I wanted to have it judged.
I also have questions concerning the door and vent glass.
Driver side door glass is date marked as "UA". It is not tinted and has markings on the left as "AS2" and at the bottom "M51". Dont know what the M51 means and the UA I think indicates a date of July of 66. If this is correct I have to surmise this glass is a replacement piece as it is after my build date??
The driver side vent glass is also marked "AS2" and has a date code of "AJ", which I believe is September of 65. At the bottom it shows "M51".
The passenger side door glass shows "AS2" and has a date code of "AJ". At the bottom it shows "M51".
Finally the passenger side vent glass has no markings whatsoever.
Ive attached some pics to support the question of deciphering exactly what I have here.
I would like to have the proper glass on the car in every respect if possible.
Any help is appreciated.
Tks
Dan

[Edward B.]

Re: 66 glass identification

Dan, THIS should answer your questions.

Ed

[Dan M.]

Re: 66 glass identification

Tks Ed,
So M4 refers to "tint". And M51 refers to door glass which adds up. The date code of UA appears to indicate this is not an original piece ( I think).
The vent glass has M51 as well which is inconsistent. It should M52 according to the research report you had forwarded unless I am not reading this correctly. So this is a bit of a mystery to me.
Tks for the help.
Dan

[Dan M.]

Re: 66 glass identification

Looking further online it seems others have vent glass indicating M51 as well. So maybe the driver side vent is correct after all? I'm guessing the driver side door glass was damaged and replaced with glass dated at a later date than the build date. Only makes sense. And the passenger side vent glass was replaced with a non OEM supplier, thus the " no markings " at all.

[Dino L.]

Re: 66 glass identification

The M numbers refer to the family of construction on tempered side windows it is thickness and color. Check the sealing tape to see if it is the same left to right

[David H.]

Re: 66 glass identification

Dan,

AS1 is the clearest, laminated windshield glass. AS1 can be used anywhere. (Most expensive so most often only windshields)
AS2 is tempered, door and rear windows
AS3 is Privacy glass, Laminated or Tempered glass with less than 70% transmission (e.g. t-tops)
AS4 is clear Acrylic Plexiglas (1953-55 Side Curtains)
AS5 is Dark Acrylic (less than 70% transmission) (C4 "clear" tops)
AS6 is flexible vinyl plastic (convertible top rear windows)

The "M" numbers are manufacturer assigned glass construction numbers. "M" numbers began showing up in Corvette glass in 1965. You would need their manufacturer records to decipher what the code means.

DOT glass manufacturer codes (DOT15 is LOF) were assigned in October 1968 and began showing up in Corvette glass during 1969. DOT codes showing up on 1968 and earlier cars would indicate the glass had been replaced.

Windshield only tinted glass on your 1966 would indicate RPO Code A02 (A01 all tinted glass)

You are correctly decoding dates from your examples.

Curious about the passenger side vent glass having no markings. Sure they are not just faded? All the window glass should have a glass manufacturer's "bug".

If you are looking for new replacement glass it will come with a DOT manufacturer code by law. As noted earlier, your 1966 would not originally have DOT manufacturer codes. Sounds like you have a pretty nice windshield - trying to get a proper date coded one from salvage in better condition than what you have will be $$$. May be better off leaving well enough alone.

Dave

[Dan M.]

Re: 66 glass identification

Thats excellent Dave tks for the post.
I'll look again for any marks on the passenger vent glass.
Yes the windshield is in really nice shape with the exception of the wiper scratches as noted. Based on everything I've read I'd have to agree, I'm better off staying with the original.
Great info tks Dave.

[Dan M.]

Re: 66 glass identification

Dave,
You were right, there is a marking on the passenger side vent glass. Its so faint I can't yet read it, you can inly see it in the right light. I need a magnifying glass and a better light and better eyes but somehow I will figure it out. Thanks I'll post what I find out.
Dan

[Dan M.]

Re: 66 glass identification

The passenger vent window has all the right markings similar to driver side vent with the exception that the date code is "VJ". Which would indicate a December 65 date.
Very tough to see but it is clear.
Tks again
Dan