LOF window codes
 

Looking for an answer that I can’t seem to find anywhere. My window codes are not matching but both combinations end in the number 7. Most GM passenger cars only have two letters which designate the month and year the window was made, which is also about 2-3 months before the build was completed. As I mentioned, my truck has two letters and the number 7. Does anybody have any idea what the number means? Is it a GM plant number? Something else?

Re: LOF window codes
 

Here’s a few more from my collection. Most end in 7 but one ends with a 10. Any ideas?

Re: LOF window codes
 

I guess that code denotes model number for the piece of glass

Re: LOF window codes
 

I stole this from Chevelles.com posted almost twenty years ago by AZCamino.

Codes are two letters like NT where N = January and T = 1970.

Month codes: N January, X February, L March, G April, J May, I June, U July, T August, A Sptember, Y October, C November, V December

Year codes: G 1964,1977; J 1965,1978; A 1966,1979; Z 1967,1980; X 1968,1981; V 1969,1982; T 1970,1983; N 1971,1984; Y 1959,1972, U 1960,1973; L 1961,1974; I 1962,1975; C 1963,1976

The above is for LOF glass. PPG glass is dated differently. In 1966 the codes were a 1 or 2 digit month followed by a single digit year. Example; 85 = August 1965 It appears that PPG later switched to a julian date (day of the year) followed by a single digit for the year. Example would be 2579 for the 257th day of 1969. A reply to one of my posts by Shawn shows examples of this.

Edit: I have since learned that the first two digits are a plant code followed by month of the year and the last digit is the year. So 2579 would be plant 25, 7th month (July), and 1969.

Re: LOF window codes
 

hi guys, I am the third generation in my family that worked for lof. I worked at the lathrop plant from 1972 to 1981. the number we are talking about was a plant code. lathrop ca was #9. that being said the letters could have been dates. I have seen many #9,s in cal cars and trucks. but this does not mean all west coast assembly plants used #9 glass. my fremont ca gmc has #7 glass. so the search goes on. BROWN 70

Re: LOF window codes
 

Awesome, thanks Brown 70. I tried to search for LOF plant #7 and I couldn’t find anything. My truck was built in Atlanta. Does anybody here have an original 1969 or 1970 truck from Atlanta that could share their LOF #’s. I’m assuming Atlanta would have received most of their glass from the same source during this time frame. I’m trying to reproduce my glass as accurately as possible, since this glass I took out is coded as 1972. This is obviously not the right glass for my 1970 with a build date of 12/69.

Re: LOF window codes
 

Great information

Re: LOF window codes
 

Im wondering if the lof in Shreveport la. is plant #7 my grandfather was plant manager for a time there. It is also close to atlanta. so maybe plant #7 ? BROWN 70

Re: LOF window codes
 

Here’s a good breakdown targeted toward Camaros that lists at least some plant codes: http://www.camaros.org/glass.shtml#LOF

Re: LOF window codes
 

hi, I think deadhead nm,s list for lathrop is correct for plant #10. must remember that was 50 years ago. LOL. for some reason #9 stuck in my mind. lathrop made all forms of autmotive glass. gravity bent windshields tempered back lights and tempered and curved side glass. the side glass area was called tufflex. lathrop also made alot of large flat glass at different thicknesses. you would be amazed how much was being done there. at times we ran 24-7. we would work 2 weeks days 2 weeks swing then 2 weeks graveyard. good thing I was young. BROWN 70

Re: LOF window codes
 

The side windows in my Fremont-built 68 are marked LX-10. So based on the info above, that would be March, 1968, Lathrop. My vent windows are LX-7 and my back window is GX-10 (April). I find this very interesting. I live about an hour and a half from Lathrop. Based on the build date project, my truck was built in May.

Re: LOF window codes
 

Hi PJ. It sounds like your truck is quite original. The dates make sense to me according to what I’ve researched. The vent window are typically two to three months before the actual build date and the front/ rear windows about one month before the build date. It is interesting that you have both a 7 and a 10. Thanks for sharing this info. I’m hoping somebody with an original Atlanta truck can chime in with what they have, 7, 10 or some new number we don’t even know about yet.

Re: LOF window codes
 

This web page has the following list:

LOF Glass Plant Code
3= Sherman,TX
4= East Toledo,OH (tempered)
5=Ottawa,IL
6=Rossford,OH
7=Ottawa,IL
8=East Toledo,OH (laminated)
10=Lathrop,CA
16=Breckenridge,PA
C=Collingwood,ONT Canada

https://nastyz28.com/threads/70-owne...ss-info.27181/

Re: LOF window codes
 

Sorry but my 1970 C10 isn't an Atlanta truck, it's a St. Louis truck built in 11-69. Originally sold in Paris TX.

All the glass appears to be original.

The LOF codes are as follows:

Windshield - YV7 - Oct 69 - Ottawa,IL
Back Glass - AV7 - Sept 69 - Ottawa,IL
DS Vent - TV7 - Aug 69 - Ottawa,IL
DS Door - YV7 - Oct 69 - Ottawa,IL
PS Vent - AV7 - Sept 69 - Ottawa,IL
PS Door - YV7 - Oct 69 - Ottawa,IL

Re: LOF window codes
 

I find it interesting that there are two codes for ottawa il. doesnt seem correct in my opinion. I never saw any lof plant that had two codes?? BROWN 70

Re: LOF window codes
 

That list has East Toledo, OH on there twice as well, for tempered vs. laminated. Could that also have been why there were two Ottawa plant codes?

Re: LOF window codes
 

Yeah, I though that was odd too. I had the same thought as pjmoreland about the duplicate Ottawa codes. I just filled in the month/year and plant info according to the info that has been mentioned in this thread. I found it interesting since I had never paid much attention to the codes on my glass.

Re: LOF window codes
 

In my time at lathrop as stated prior we made tempered and laminated glass. all were marked #10. things can get muddy with anything automotive especially when the trucks are this old. generally, I would say the info here is very good. just question the double plant codes. good stuff, BROWN 70

Re: LOF window codes
 

Everybody’s input so far is very helpful and appreciated. Cericd, the info on your truck here is especially helpful. 7 seems very common from East to West coast. With a few 10s mixed in, I’m starting to wonder if 7 and 10 were the truck glass supplying plants. Does that make any sense BROWN70?

Re: LOF window codes
 

This might help ? :chevy:

http://www.nags.net.nz/image/cert/DOT_list.pdf

Re: LOF window codes
 

yeah anything is possible. at lathrop all I saw was #10 we made chevy glass olds glass and buick glass. much of the glass fit similar cars. a bodys etc. our q.c. division would come by the tempering area at least once an hour and break the glass to see if it was tempered correctly.( breaking into small enough pieces). i.e. at lathrop we made glass for many model gm cars and trucks. we moved to ca. in 1963 so my dad could work there from rossford ohio. BROWN 70

Re: LOF window codes
 

Not sure if I'm understanding all this code info. After looking at the PDF provided by Grumpy I noticed that below the word "Laminated" it says DOT 15 M23. Every piece of glass on my truck with a LOF code says DOT 15 on it. According to the PDF DOT 15 is Libbey-Owens-Ford Co - Toledo, OH. A little Google search told me that LOF's corporate headquarters was in Toledo. I wonder if the PDF is a more "current" list that wouldn't apply to these old trucks? Here's a pic of the LOF information on my windshield.

Re: LOF window codes
 

In summary, this is the info that I accumulated. It is probably still not be complete, so please feel free to add more. In the case of my 1970, I have all of the info I need.

LOF Glass Markings
https://www.dropbox.com/s/d2czb90s5f...yout.png?raw=1

Soft-Ray
This indicates that the window was tinted from the factory. It will be green in tint. If the marking does not include Soft-Ray, then the window will be clear.

FLO-LITE
The truck glass was manufactured by three different processes; Plate, Float (Flo-Lite), and Laminated. 90% of the examples I found for our glass were marked Flo-Lite and Solid Tempered. Plate windows were also marked with Solid Tempered. Windshields are the only piece of glass that were laminated. They were marked with FLO-LITE and Laminated.

Date Codes
Codes are two letters. This define where and when your glass was made. An example would be NT where N = January and T = 1970.

Month codes: N January, X February, L March, G April, J May, I June, U July, T August, A September, Y October, C November, V December

Year codes: G 1964,1977; J 1965,1978; A 1966,1979; Z 1967,1980; X 1968,1981; V 1969,1982; T 1970,1983; N 1971,1984; Y 1959,1972, U 1960,1973; L 1961,1974; I 1962,1975; C 1963,1976

Windshield- glass made 1 month before your truck’s build date
Vent- glass made 2-3 months before your truck’s build date
Door- glass made 1 month before your truck’s build date
Backlight- glass made one month before your truck’s build date

Plant Codes
The most common plant code on all of the examples I found was Plant 7. I did however see a small percentage of windows marked with Plant 10. Plant code marking seems to be mostly common with GM trucks as you don't find these much on passenger vehicle glass markings.

LOF Glass Plant Code
3= Sherman,TX
4= East Toledo,OH (tempered)
5=Ottawa,IL
6=Rossford,OH
7=Ottawa,IL
8=East Toledo,OH (laminated)
10=Lathrop,CA
16=Breckenridge,PA
C=Collingwood,ONT Canada

LOF Glass Models
https://www.dropbox.com/s/f45e6uzb8e...dels.png?raw=1

DOT Number
This number defines the manufacturer of the glass by a number given by the Department of Transportation. All LOF glass will say DOT 15, which tells you Libby Owens Ford made it.
https://www.dropbox.com/s/yg9x3rjdtrzelur/DOT.png?raw=1

Marking Placement
Windshield- bottom corner, in front of passenger seat, seen from inside

https://www.dropbox.com/s/sj9si0pw5b...ind1.png?raw=1

https://www.dropbox.com/s/j829kkkx9q...ind2.png?raw=1

https://www.dropbox.com/s/3v8junk8fm...ind3.png?raw=1


Vent- driver forward of hole seen from inside, passenger forward of hole seen from outside

https://www.dropbox.com/s/51lp3nxi79...ent2.png?raw=1

https://www.dropbox.com/s/awp2yipsf5...ent1.png?raw=1

https://www.dropbox.com/s/klajh7fsd8...ent3.png?raw=1


Door- bottom corner, near vent window, driver seen from inside, passenger seen from outside

https://www.dropbox.com/s/475sytty74...oor2.png?raw=1

https://www.dropbox.com/s/vmov5ygnvk...oor1.png?raw=1


Backlight- bottom corner, behind driver, seen from outside

https://www.dropbox.com/s/hzerfriy3y...ack3.png?raw=1

https://www.dropbox.com/s/v7esoi8vp5...ack1.png?raw=1

https://www.dropbox.com/s/20hqbwi72o...ack2.png?raw=1



Thanks again for everybody's help. This will help me recreate the windows I need for my build. I did a bit of research on companies out there that offer remaking these logos on plain glass. For years, the two companies have been Pilkington Classics and Auto City Classic. It seems that people have preferred Pilkington due to how well the glass is made in thickness and shape. Plus, Pilkington actually bought LOF back in the day so they have that going for them too. I found several people that were happy with Auto City Classics but it sounds like the glass in made not in the USA and a few folks claim to have issues with this. I decided that Pilkington is probably the way to go and gave them a call. After several attempts to get somebody that knew what I was talking about, I was told that Pilkington (parent company) absorbed the Pilkington Classics line back in 2021. They will continue to reproduce glass for classic cars but have discontinued the logo etching service. They weren't even sure where the stencils ended up. So, I decided to give Auto city classics a shot. I talked with Dave as he seemed to be the expert in LOF markings. I had to email the examples of what I needed so they can make custom stencils for my LOF markings. There is a setup charge for each one. They quoted about three weeks for a custom order like this. I went ahead and placed my order and I will report back with how everything turned out.

Re: LOF window codes
 

Did ppg glass come stock or do I have a replacement in my truck.
1 ppg 1 lof wind wing

Re: LOF window codes
 

PPG was also a stock factory window possibility. This thread is just the specifics for LOF window codes as it pertained to my build and my original question in post #1. I didn’t research any PPG specific codes.

Check out this link for some info on the PPG windows.. The website is for Camaros but some of the glass info pertains to our trucks too. http://www.camaros.org/glass.shtml#PPG