The Stovebolt Site Forums The Shop Area General Truck Talk A Tyre Date Code deciphering question?

No, I din't miss spell that again, since these tires were mfg in Ballymena, Ireland I thought it appropriate to label it that way. But to the question; I’m sure Bill has an answer for this one. Pryor to 2000 the DOT date codes supposedly were three digits numbers and after 2000 the were four, zat sound correct?
For the past week I've been taking inventory of my newly acquired '54, 3600 truck. The tires are brand new (looking) Hercules Super Express II 7.00-15LT (6 ply rated) 4 Nylon Cord Plies (whoopee). So why does the DOT UPNV HJ3497 stamp appear on the inside of the side wall??? Obviously the code means 34th week of 1997 but why does it have four digits in the code instead of three???
Denny Graham
Sandwich, IL

Is there a number on the outside sidewall? I ask because the DOT number should be 12 digits total (11 prior to 2000) and some manufacturers do put a partial number on one side, and the full number with the date code on the other.

The date code could mean 349th day of a year ending in 7. In the past there was no way to specify the decade so you dont' know if it means 1997 or 1987. I think the HJ is the manufacturers code for the specific plant where the tire is made. Joe

Ok I was wrong above. I do remember trying to date code the old original tires on an old Rambler I bought. But the post-2000 date code is supposed to have four digits.

The first to digits represent the week of the year (34th week in your case) and the last two digits are the year. That replaces the old three digit code where you had to guess at the year since the decade was not represented in the code. Joe

If you're not sure how old the tires are, they're too old to drive on. I have retreads on my truck that are 15 years old with lots of tread left.

Some of the sidewalls look perfect, some are cracked. I don't want to die. Generally anything over 5 years old is needing replacement for safety reasons. I'm not saying people don't use older tires, but it's risky.

I updated the number exactly as it is on the sidewall Bill. It's only on one side of the tire. "DOT UPNV HJ3497" here’s a pix of it: http://www.pbase.com/dennygraham/image/129095696/large

A lot of factors enter into whether a tire's shelf life is expired or not. From a legal stand point when the law dogs get their teeth into the case, they stand a good chance of convincing a jury of non-automotive types (which they would hand pick for the jury of course), that the tire is "Unsafe at any Speed" if that tire is older than a couple of years. But if the vehicle has been garaged and driven only a couple of thousand miles a year and the rubber is not hard and cracked then you would have a hard time convincing me that a catastrophic failure is about to happen at 45 mph. A handful of tire failures out of the millions and millions of tires sold every year also does not wash with me. I wouldn’t be surprised if half the tires on the US highways are “out of date” and it is extremely rare to see catastrophic failures these days even with the high speeds we drive at nowadays.
Denny Graham
Sandwich, IL

Good points, Denny!

Having spent 5 years or so working in a tire manufacturing plant, I'm of the opinion that there's a lot more danger involved in whether or not the tire builder was drunk, hung over, or trying to meet his quota for a particular day's production than whether or not a well cared for tire is tecnically out of date by the sidewall code. I worked in a relatively small factory, and we produced 15,000 tires during a normal 24-hour production period. I'm sure there must have been a few that got into the warehouse with less than perfect construction, curing, or quality control. The deadly Firestone/Ford Explorer tire problems of a few years ago were mostly the result of inexperienced scab tire builders' assembly mistakes during a strike, plus the use of out-of date materials.
Jerry

If a tire is manufactured off shore to be sold in the US it will have a US date code. Any pre 2000 would have 3 digits. If it was manufactured in the UK for sale in the UK or another country, it would use their date code. Apparently these tires were not manufactured for sale in the US. Tires manufactured for sale in Europe since 1997 have an "e" number is when the tire is 6 years old and will no longer pass safety inspection. However, bias tires are not prone to blow out like radial tires. I have some pretty old textile tires on my jalopies and don't worry about them.

I did some more research and found this. They could be 1997 tires based on this. Text from website in quotes.

"Here are the rules:

First locate the letters "DOT" on the sidewall of the tire. Nearby will be the DOT code. DOT codes are 10 to 12 digits long. BTW the digits can be numbers or letters.

The first 2 digits are a code for the manufacturing plant.

The next 2 digits are a code for the tire size.

The next 3 or 4 digits are a code for the type of tire.

The last 3 or 4 digits are the date code. The format is week/week/year/year or week/week/year. These are always numbers.

Starting in the year 2000, the date coding used was 4 digits. That means the largest number you should see for the year code is 09. Before 1999 the format was 3 digits. 1999 and 2000 are transition years, so you will find both 3 and 4 digits.

The date code only has to be on one side – and it is permissible for there to be a partial DOT code, so long as one side has the complete code."


The tire manufacturing (plant) codes are found here:

http://www.harriger.com/tire8.htm

It appears that Hercules does not actually have any plants with their name on them. Your tires were manufactured by Cooper Tire and Rubber, Findlay, OH based on the above. Joe

Joe, that’s the site I used for the information in the opening post. But your looking at the wrong chart. The correct chart for my DOE code (DOT UPNV HJ3497) is chart 5: http://www.harriger.com/tire5.htm
And as I posted in the opening post, the HJ means these Hercules tires are manufactured by the Michelin Tyre Co., Ltd. in Ballymena, Ireland. They were sold and installed in West Chicago, Illinois, USA.

The original intent of my question was to find out why there is a “four digit date code” in stead of a “three digit date code” if they were indeed manufactured prior to the 2000 change over to the four digit standard.
I’m about 100% sure that the manufacturing date was the 34th week in 1997, but the three digit code was not applied to these.
Denny Graham
Sandwich, IL

Denny, looking at the code, I'm thinking that the date is actualy the 49th week of '97, the 3 is part of the middle af the code.

Did you see this link Bill? it clearly is coded HJ3497 without spaces. http://www.pbase.com/dennygraham/image/129095696/original
Denny G

Yes, I did see that. But I have seen tires stamped without spaces before. I'm thinking that the code is UPNV HJ3 497.

Me too. Joe

I still think they were manufactured to sell somewhere other than the USA. A lot of tires were sold in the US that were meant for other countries in the late 90's. It was a way of dodging FET. Most of bootleggers were shut down in 98 or 99. If they were meant for the US, they would have a 3 digit date code. I bought some Michelins about that time and would up paying FET on them.

Okey dokey, time to end the guessing game and Ken, your entry makes more sense then anything I've heard so far so you get my vote. This was a transitional period for the tire industry and I’m sure there were discrepancies in the interpretation of the new standards. Since the manufacturing plant was in the British Isles my guess would be that they were made to comply with the specs of that country at the time. If they were made specifically for use in a foreign county it kind of surprises me that they would have a US "DOT" standard stamped on them, I thought that was strictly a US rather than a world wide agency.

Well, anyway, it’s no big thing guys, it was just a simple question about a discrepancy or variation from the DOT labeling standards. These split rims and tires are headed for storage along with my other set of bias plies from my ‘50, 3604. Before I do any serious driving with the truck I’ll be looking for some one piece 15” rims to mount up a good set of new (fresh) radials. I’ve had my share of bias ply Nylon tire technology for everyday driving on the other truck. Lucky I’ve still got any teeth left as badly as they would shake the first ten miles.

Part of my research on a restoration of this sort is to try and establish details of proper provenance. So somewhere by the end of the year I’m going to try to find the original owners son, if he is still alive and in the area. He was the one who took care of the truck from 1988 to April of 2010. Hopefully he will be able to fill in some of the missing facts about the trucks history and maybe even come up with some pictures or stories about it out on the farm in Nebraska. If I find him I’ll ask him about the tires and where he bought them.
Been interesting, thanks for the discussion guys.
Denny Graham
Sandwich, IL

Well wait till you hear this and it’s first hand straight from the horse’s mouth. I just got off the phone with the guy that drove this truck I bought last week, to high school in Nebraska in 1954 when he was 14 years old. His father bought the truck to use on the farm and for his transportation to school because there were no school buses out there in the country.
In 1987 when his father passed away he needed to drive the truck back here to Illinois. The tires were shot so he had five new tires put on it out there in Nebraska. So that code is not for 1997 but for 1987. The code would almost have to be 349th. day of 1987. So it looks like Joe was partially correct, sorry Ken, I gotta take that vote back.
The gentleman told me that his father originally registered the truck in his name when it was new. That means that I just talked to the original owner, and he only lives a mile away from me, and he agreed to meet with me and talk about the history of the truck, and he even said he had some pictures of the truck back in the day. Man it doesn’t get much better than that, Wowee Zowee!!!!
Man things are really coming together and it’s only been in the stable for week.
Denny Graham
Sandwich, IL

Denny,

This just keeps getting better and better. Can't wait to hear the history of the truck. Congratulations on your find.

Denny, I don't see the Ss DOT on the tire. Only DOT. Tires in Europe have DOT on them. The law which went into effect in 1966 rquired tires to be marked with 3 digits. The week and the last digit of the year. I don't question that your tires were produced in 1987. The day in question happens to fall on a Sunday. But I do question that they were made to sell in the US

Well the original question still remains Ken, if the pre 2000 standard was "three digits for the date" then why are these tires stamped with a "four digit code"? As far as the year of manufacture goes, that had to be 1987 or earlier. As I explained, I got that straight from the guy that paid the bill to have them installed, back in 1987 at a shop smack dab in the middle of the good old US of A, so that date we know for sure.
And again, all of this is irrelevant because these wheels are going into storage shortly and will only go back on the truck if I should ever get to the point I wanted it judged for originality. I don’t have a problem running a tire that’s six or eight years out of date but a quarter of a century is a different story. So in the future the only time these tires would see the road might be a short trip to or from a local show and then only if I were concerned with having it judged, and that really is not my bag.
I am however getting a good education on the history of tire labeling and learning about these old trucks is my bag.
Oh, by the way, what is "Ss DOT"? Making tires on Sunday? Sure, don't ya know that us Irishmen work seven days a week; there is no rest for the wicked!

Denny Graham
Sandwich, IL