Goodyear Wide Tread GT E70-15 question

[Charley Lillard]

date

[JChlupsa]

DOT Number
All tires sold in Canada must have the "DOT" ((Department of Transportation), or tire identification number, moulded into the sidewall. Our tire has a DOT number of GHYT 4501. The first two characters after DOT indicate the manufacturer; the second two characters indicate the plant where the tire was manufactured.

Next you may see an optional string of three to four characters. Our example does not include this code. Most manufacturers use these to record company specific information about the tire, and, if necessary, use them as a guide when issuing product recalls. Because they are company specific, these codes are not standardized and are meaningful only to the manufacturer.

The last three or four digits give the date the tire was made. For all tires built after 1999, this will be a four-digit number with the first two digits giving the week number, and the last two giving the year. For many tires built previous to 2000, the date indicator will consist of three digits, the first two giving the week number and the last giving the last digit of the year. In our example tire, the last four digits of the DOT code are 4501, so our tire was made during the 45th week of 2001.

[AMANOCC]

From a 69 Corvette "Stingray Guidebook" by Rick Bizzoco.
UY05D81 U=1969 (year of production, Y=May, O= Goodyear (Manufacturer), 5=Gadsden,AL (Location of Plant),D8 (these two positions are noted as "size of tire" but no chart was avaiable, 1 ("type of tire" again unknown).

TCO551D T=1968, C=Sept, O=Goodyear, 5=Gadsen, 51=unknown, D=unknown.

MDUY DJA162 M=Goodyear produced domestically D=Plant code(no chart), UY=tire size (no chart), DJ=tire type (no chart), A=Internal use code(optional), 16=week of production, 2=year of production (1972,1982??) Note: "a new DOT code initiated after May 22, 1971, this was a 10 character code".

Charlie, hope this helps....Alec

[Charley Lillard]

Thanks..so it sounds like the Vytacord polyester cord tires were probably made in 1972. Did they still make Wide Tread Gt's in 1982 ?

[ohhawk]

Not sure what the question is but.....

* E70 x 15 on a '69 Z doesn't sound right to me. Maybe I'm missing something with the title in your post. I usually associate this uncommon size to the Chrysler line for Dodge Demon / Plymouth Duster, back around this timeframe.

* Tire companies were going through lots of changes in late 60's into early 70's moving from nylon to polyester to fiberglass or a combo of each. Each material component stayed in most tire mfg.s lines for quite awhile. Nylon usually = affordable, polyester = comfortable ride, fiberglas belted = best mileage.

* Terms such as Vytacord, Polyglas, Supertread, Custom Cushion, were all brand names for each companies version of some of these compounds used in the tires. They all touted a different twist but it boiled down to nylon, rayon, polyester, fiberglass.

* Some of the RPO options in '69 show that you could get a 2 ply tire or the "new" fiberglass tires. The 2 ply might have been either all nylon or all polyester or 1 ply of each I don't know. All nylon tires were fast moving the way of the dinosaur at this point.

Don't know if this helps or not.

[Charley Lillard]

E70-15 wide tread GT is probably the most common of 69 Z28 tires. E70-15 was the designated size for a 69 Z28.

[Lynn]

I thought all the 69 Z/28's came with E70-15, correct? Also all the 9737 COPO cars? I guess some had Firestones, but I have never seen them, only the Goodyears.

Back to dates. Now I am confused. I have an early Wide Tread GT 4 ply Nylon tire that I always thought was the original spare on my car. It has only been on the ground once or twice. Date code UFO5C23. I was told by someone on this board that the tire was a mid 70's date. Does the "U" indicate 1969 manufacture? What month would the F indicate? How did "C" come to be September?

I would post a pic, but one of my kids took my digital camera on vacation.

Lynn

[BillD]

I have a Vytacord WTGT that is being used as a spare for a 68Z. I did research on it some time ago and concluded that it was not the original tire from 68. I seem to remember that the Vytacord was a very early replacement tire. I would be happy to dig out the date code if it helps.

[Lynn]

So what does Date code UFO5C23 translate to?

Lynn

[Dusk Blue Z]

Who knew decoding the tires would so complicated?

I do some work in a Goodyear plant and the white numbers on the tread are their part numbers used when assembling the tires. You may be suprised by how many "parts" are used to make a tire. Back in the day all tires were hand assembled. After they were assembled they were cooked in the mold to valcanize the rubber together. Heat will take a tire back apart, that why you see treads of truck tires on the highway.

The date codes were screwed into the mold every day just like the casting numbers on engines.

Mike