Topic: Decoding Date Codes on Original Tires

[Anghelrestorations]

I have been trying to find a way to decode the manufacture's date code the original Polyglas tires are stamped with, to determine what era they are from.  Does anyone know of a printed resource for this?
In particular looking at Goodyear "no size" Polyglas tires that would originally have been used on 69 Mustangs.   

My understanding is that at the time the manufacturers wanted to make it so that the average consumer could not read the date codes easy to avoid having tires on the shelf that buyers did not want....much like older milk in the grocery store...since buyers would want the newest tires, not a tire that was on the shelf for 8 months. 

Any thoughts?

[J_Speegle]

Been talking about doing an "article" thread for the site with Tim Lea. Have the pictures assembled  just have to get the info out of his head and on to paper

[Anghelrestorations]

The general guideline I have been using is looking at the number of digits and letters in the date code stamped into the tire.  Most date codes I have ever seen are on the back side of the tire (opposite side of the raised white letters)...but I have seen some stamped on the front. 
For a 7 digit code it is roughly 67 - 69
For a 8 digit code it is roughly 68 - 69
For a 10 digit code it is roughly 70 - 71

So for this example I would say it is an early tire versus a replacement from the early 1970's.  Thats the best guess I have for now...

[TLea]

We should get it down on paper, my memory is fading. You are correct about the codes not making sense to the average consumer, never heard the "old milk" theory but it is plausible.
J=1969
S=April
05=plant code (i can't remember what this on is but I should be able to find it somewhere)

[PerkinsRestoration]

    05= Gadsen, plant code

[Anghelrestorations]

Okay, I still cant see how this makes sense.  Here is a list of tires with the date codes...I dont see a pattern...but like I said they did not make this easy to decode.  These are from 8 tires I could find tonight in my shop:

AFNFL8DS
TS01175
JS05B50
JC055C6
LK41008
TE01994
TE91001
UT41092

[J_Speegle]

Looks like this is going to be an ongoing discussion so I'm moving it so others can find it in the future

[thefordshow]

Bob P. did an artical in Mustang Monthly"resto-round up" May '97 page 16 on Goodyear Tire deciphering charts.

[TLea]

Okay, I still cant see how this makes sense.  Here is a list of tires with the date codes...I dont see a pattern...but like I said they did not make this easy to decode.  These are from 8 tires I could find tonight in my shop:
It doesn't make sense, thats the point

I'll just do the dates

AFNFL8DS  don't know, probably 73 or later when coding changed again to TIC system
TS01175  April 68
JS05B50   April 69
JC055C6  Sept 69
LK41008  Oct 68
TE01994  Nov 68
TE91001  Nov 68
UT41092  Jan 69

Its hard enough for these thorobred/unrestored guys to find tires, maybe we should really make it difficult by reading the dates now   

[rockhouse66]

Bob P. did an artical in Mustang Monthly"resto-round up" May '97 page 16 on Goodyear Tire deciphering charts.

Perhaps someone could scan this article and post it for all to see?

[Anghelrestorations]

I found the article...I can scan it tonight when I am back home. 

Marcus

[Anghelrestorations]

[J_Speegle]

Marcus thanks for posting

[Anghelrestorations]

Seems there is still a contridiction between the date codes and the data I posted from the Mustang Monthly article if you look closely. 
If you look at the first letter in the date codes I listed earlier, and take the letter "T" as an example, this could be from any number of years including 66, 67, 68, 69 and 70.  Cant really see how this would be narrowed down to 1968 exclusively.  The letter codes overlap during the years...so maybe the data was misprinted or something is missing here. 

[J_Speegle]

Not sure but there can be mistakes made in both magazines and posts. Believe Tim worked in a tire distribution center (he will need to confirm - but think that is it) when he was a little younger so he has first hand experience