date codes

[poppa]

Can anyone explain how to read the date codes?? You know,on the trans or wiper motors or.....Thanks

[twinscrew698]

This might help ya understand!!!
Hope it helps ya!
http://www.mymopar.com/index.php?pid=31
And check this one out..
http://www.mmcdetroit.com/Understanding_Date_Codes/

[poppa]

In your second link,ref ref e1 ,four digit day and year,3301=330th day of 1971.Would this be the actual 330th day or would it start from August 1?? Thanks for the reply....

[maxwellwedge]

That type of date coding starts January (Day of year/year). There are other codes which are based on a 10000 day calender. You need a 10000 day calender for those. They are typically ued for transmission and some engine dates. I wrote an article on date coding once - I'll see if I can dig it up.

[poppa]

Thank you. I just saw the 10000 day calender and don't see how you get oct 9 1969 out of 2995.

[hemigeno]

Thank you. I just saw the 10000 day calender and don't see how you get oct 9 1969 out of 2995.

If you start counting at July 29th, 1961 and include leap days when appropriate, it does work.  I suppose that was the beginning of the 1962 model year, but the significance of that is beyond me.   

[RD]

i have a excel spreadsheet (that I did not create) that automatically does the calculation of the 10,000 day calendar for you based upon your stamping.  it can be found here under the tools section on the right hand side:

http://rpmtopeka.org

[poppa]

RD,I click on the link and it says something about the pathway. In other words,it's not working. I'll keep trying  though...

[RD]

RD,I click on the link and it says something about the pathway. In other words,it's not working. I'll keep trying  though...

not sure what to tell you.  i checked on the link in both mozilla and in IE8 and both allowed me to save the file.

try here:

http://rpmtopeka.org/10000DayCalendar.xls

[poppa]

All I get is     number 1   and            July 29 , 1961


The rest is blank. Am I doing something wrong??

[maxwellwedge]

What part are you looking at and what is the date on it?

[poppa]

It opens up as a bunch of rectangles and in the upper let corner this is all that is there??

[maxwellwedge]

What part are you looking at and what is the date on it?

I was talking about what parts are you looking at and what are the dates on them. Post them, I tell you the dates and show you how to do it yourself from then on.

[RD]

All I get is     number 1   and            July 29 , 1961


The rest is blank. Am I doing something wrong??

go ahead and replace the "1" with the 10,000 day date that you want to decode and hit enter.  the date will show up in column B showing what date it was assembled.

[poppa]

OHHH,Thank you,I'll try that as soon as I get home.

[poppa]

Nope. I put in 0177 and it just turns to 177.

[maxwellwedge]

0177 doesnt sound like a 10,000 day date - Sounds like the 17th day of 1967 or 1977. What part are you looking at? Could also be a vendor number.

[RD]

0177 is 21 Jan 1962 on the 10,000 day calendar

make sure after you put in the number, you hit "enter"

[maxwellwedge]

Here is an article I co-wrote years ago on date coding... Hope it makes sense - I am copy and pasting from the original Word doc. The pics are there - just not in the right order.

In this issue we will look at all those parts and start noting date codes as well as part and casting numbers. This will help our restoration in a couple of ways. First we want to be sure that we have the proper components as they relate to the build sheet and factory specifications. Secondly we want to be sure the components that are date-coded have proper dates that fall within the scheduled production date of the vehicle.

The date coding of parts was and still is the vendors' method of tracking when each part was assembled. This was mandatory for warranty purposes in case of parts failures.

This in itself has become probably the one most difficult thing to deal with when restoring a Chrysler manufactured car. Finding a correct part numbered part is difficult in itself, but when the part has to be correctly date coded also makes the task impossible at times. The proper date code on a part also commands a higher price. Practically every part on the car has some sort of date coding on it whether it is cast, stamped, etched or inked on.

We all know that a motors cylinder block is date coded but did you know that a starter relay is date coded or the diodes in your alternator?  How about the accelerator cable, brake hoses, oil pressure and water temperature sending units or the thermostat housing. How about motor mounts, drive shafts, u-joint straps, hood latches, windshields, voltage regulators, coils, carburetors and on and on. I will attempt to explain the various types of date coding used throughout Mopar.  

Several different types of date coding were used during the muscle car era. Some are very easy to spot and done in an easy to decipher manner while others require some close examination and thought to find and recognize them as a date code. I'll start off with the most conventional date code method: Month/Day/Year. This method is used on most cast iron parts such as cylinder blocks, cylinder heads, intake and exhaust manifolds. Example: 8  19  69 = August 19th, 1969.
The Month numerals are as follows:

1=JANUARY   5=MAY   9=SEPTEMBER
2 =FEBRUARY   6=JUNE   10=OCTOBER
3=MARCH   7=JULY   11=NOVEMBER
4=APRIL   8=AUGUST   12=DECEMBER

The day is often not used in the numeral type date codes. For instance, windshields and other glass in the car are coded with the Month/Year. Example: 26 – February 1966.
The glass code is incorporated into the manufacturers screen that is etched into each glass. On windshields and rear glasses this is typically located at the lower middle of the glass. The date code is typically the lower right hand set of numbers. On side glasses it is located in the lower corner of each glass.

Some types of Month/Day/Year date codes substitute the month numeral with a letter. On many of this type of date coding, the Day numerals are deleted leaving the Month/Year. Typically A is January, B is February and so on with the exception of the letter I which most of the time was deleted because it could be mistaken for the number 1.
The month letters are as follows:
A=JANUARY   E=MAY   J=SEPTEMBER
B =FEBRUARY   F=JUNE   K=OCTOBER
C=MARCH   G=JULY   L=NOVEMBER
D=APRIL   H=AUGUST   M=DECEMBER





We will now show the different coding used for various parts.



JULIAN: DAY OF / YEAR    (1-365 / LAST DIGIT OF YEAR)

The DAY OF / YEAR method of date coding is typically used in the following applications:
•   Carburetors
Carter - on tag
Holley - on air horn
•   Hood Catches
•   Hood Latches
•   K-Frames
•   Master Cylinders
•   Wiper Motors   The wiper motor photo above shows the part number - 3431077, the vendor code - 73691 and the date code - 2869 - The 286th day of 1969 This just precedes the build date of this car.


WEEK OF  / YEAR   (01-52 / LAST DIGIT OF YEAR)

The WEEK OF / YEAR method of coding is usually found on the following components:
•   Horns
•   Ignition Coil
•   Voltage Regulator
•   Distributor
•   Exhaust Manifolds   The horn photo shows the date code 39 9 - The 39th week of 1969. The other horn (not shown) is coded 40 9 - The 40th week of 1969.










MONTH OF / YEAR    1-12 / LAST DIGIT OF YEAR

The MONTH OF / YEAR coding is found on the following components:
•   Glass
•   Outside Mirror(s)
•   Wheel (not all)   The rear side glass photo shows 69 - The sixth month (June) of 1969. Glass dates can differ greatly on a car - sometimes many months from one piece to the next.


MONTH OF (Alpha)  / YEAR    
(A-M / LAST DIGIT OF YEAR)
The MONTH OF / YEAR Alphabetical coding method can be found on the following components:
•   Carter Carb Base
•   Carter Fuel Pump
•   Oil Sending unit
•   Temperature Sending Unit
•   Driveshaft (some)

The oil sending unit shown is dated K 9. The K is for the 10th month (October) and the 9 is for 1969. A =January, B = February etc. The Letter I is skipped so that it is not confused with the number 1. This is very close to the build date of the fish (Scheduled Production Date of October 12, 1969) but possible.


The driveshaft shown is part number 2863656. The last 2 digits (56) correspond with the 2-digit number on the build sheet. Also visible to the right of the part number is the date code H 9. The H is for the 8th month  (August) and the 9 is for 1969. This is not our Cuda's driveshaft. It was a little too rusty for our photos to clearly show the part number and date codes. We were able to find the 2883775 part number which corresponds with the build sheet and a date code of G 9 on it which translates into the 7th month (July) of 1969. This is three months before our Scheduled Production Date, which is also possible.

[maxwellwedge]

MONTH / DAY / YEAR   1-12 / 1-31 / LAST 2 DIGITS OF YEAR
The MONTH / DAY / YEAR coding method can be found on the following components:
•   Exhaust Manifolds (Some)
•   Intake Manifolds (Some)
•   Manual Transmission
•   Water Pump

The exhaust manifold above is dated 8.19.69, which is August 19, 1969. This translates into being cast about seven weeks before the vehicles Scheduled Production Date. The casting number is 2951865, which is the correct part for this application.

The cast iron six pack manifold above is dated 7 16 69 which is July 16, 1969. This is almost three months before the scheduled date of the car. This is one of the earliest casting dates we have found on the cast iron 440-6 intake.

















MONTH / DAY     1-12 / 1-31
MONTH / DAY coding is used on:
•   Engine Pads (not all)
•   Wheels

The engine pad shown contains the following information.  F = model year - 1970 (B = '66, C = '67, D = '68, E='69 etc).
440 = the engine displacement. The 9 is the month and the 4 is the day the engine was assembled - September 4th.
HP means High-Performance and the 2 means it was assembled on the second shift. This engine was assembled about 5 weeks prior to the car build date. Sometimes they are earlier than that and other times they were assembled a few days before the Scheduled Production Date for the car.

   
The left photo shows from left to right M1 with a small 9 under it, which is 1969, a 9 which is the 9th month (September) and an 18 that is the 18th day of the month. Many times the year code under the M is stamped faintly and hard to read. The right photo shows the back of the wheel where the 9 is quite evident. It is sometimes stamped inside the wheel as well. These wheels were built about 3 weeks before the car was. Incidentally, all 4 wheels have the same date of manufacture on this car, which is common.

[maxwellwedge]

10,000 DAY CALENDAR
The 10,000-Day Calendar is generally used on the following components.
•   Engine Block (not all)
•   Transmission Case

The chart above is the 10,000-Day Calendar for the 1970 Model Year.

This is the V.I.N. pad of the transmission for the 'Cuda. The line worker who stamped this pad didn't notice that the last number didn't make it on. The series of characters under the V.I.N. break down as follows:
Plant Code: "PP" – New Process Gear Division
Component Code: "833" – 833 Transmission
10,000 Day Date Code: "2993" – Oct. 7, 1969
Serial Number: "0309"  - 308th unit built. This is a sequential number beginning with 0001 for each day's production.
This unit was built only 5 days before the production date of the vehicle.









BOX TYPE
The Box Type coding method can be found on the following components:
•   Thermostat Housing
•   Transmission Case

The Thermostat Housing above has the year "66" for 1966 and has 12 "boxes" to the right side of the year. These boxes represent the month. Five of the boxes are "checked" with dots for the 5th month (May) of 1966.

WHEEL TYPE
The Wheel Type of date coding can be found on the following parts:
•   Alternator Housing
•   Starter Motor

The Alternator (above) has the year (68 for 1968) in the center of the "wheel". Inside the "spokes" of the wheel are checked with dots. There are 6 spokes checked with dots. This alternator is dated the 6th month (June) of 1969.
Using the same coding system the Starter Motor below is dated the 5th month of 1969.


Other Types of Date Coding used:

Year/Month Dot Type – Motor Mounts

Month/Day – Scheduled Production Date on fender tag and build sheet.
1=JANUARY   5=MAY   9=SEPTEMBER
2 =FEBRUARY   6=JUNE   A=OCTOBER
3=MARCH   7=JULY   B=NOVEMBER
4=APRIL   8=AUGUST   C=DECEMBER
Example 1: A12 = October 12th  Example 2: 408 = April 8th

There is a date "window" on the parts that corresponds with the scheduled production date of the vehicle. It can vary from months before to a day before the build date. In any event they should always have a date before the scheduled production date. Cars were not always built on their scheduled date! There may have been parts supply or paint problems that resulted in the vehicle being built a few days or weeks after the date. If you have more than a few dates on original components that are the same or a little later than the build date then you can assume the vehicle got out a little later than it was supposed to.

[maxwellwedge]

Pics

[RD]

a 727 transmission decoded:

this will give you the serial number: ex. 0G123456  0=70 G=St Louis 123456 serial number



PK3410670L 3120 9419

the 10,000 day number is 3120 which equals 11 Feb 70.

[hemigeno]

Good info, Jim!

Thanks for taking the time to dig the text back up and post the pictures.

[poppa]

Agreed,most helpful. The calendar is working for me now. Thanks to all for the good info!