Topic: Bumper date stamp

[MustangAndFairlane1867]

I found the stamped date code on the front bumper of my San Jose, K-code car that was built on 2.16.1965 and I thought I would share the "adventure" here and pose a couple of questions.   I had been looking for the numbers on the INSIDE of my front bumper when I happened to notice the numbers on the OUTSIDE of the bumper.  They are on the driver's (left) underside of the bumper on that "tab" that sticks out above the square hole.  The numbers read:  4   8   M2.   I interpret this as the 4 standing for 1964; the 8 being a mystery; and the M2 for December 2.  As I noted above, my car's build date is February 16th, 1965, so that date of December 2, 1964 on the bumper seems correct to me.  If anyone has an idea what the 8 represents, please let me know.  In addition to those numbers, there is a 4 1/2" x 1 1/2" rectangular strip of thick, once-glossy paper glued to the inside of the middle of the bumper that bears a professionally-printed "Ford" logo at the top and underneath in large print: C5ZZ-17757-A.  I'm surprised this glue-on label has survived all these years on the bumper, and I'm not sure why it was attached to the bumper to begin with.  I was able to easily lift it off the bumper without damaging it in any way and it's now sitting in front of me on my desk as I type this.  I suspect one of the reasons it has adhered to the bumper for so long is that the car has been disassembled and sitting in my garage since I bought it in 1990, only recently getting much needed restoration attention as I work at bringing it back to life.  I haven't found any numbers on the rear bumper, but I suspect it might be an after market piece.  Please let me know if I'm mis-interpreting that "4  8  M2" date code.  Still unsure what the "8" represents.  Thanks, Ron...

[midlife]

My understanding is that anything with a C5ZZ part number represents a service replacement part, not an original factory-line assembly part.

Someone correct me if that is wrong.

[CharlesTurner]

My understanding is that anything with a C5ZZ part number represents a service replacement part, not an original factory-line assembly part.

Someone correct me if that is wrong.

+1, it's a Ford replacement part, not original to the car.

[MustangAndFairlane1867]

Thanks for the info on the replacement part information.  Makes sense.  But how do we interpret the "4  8  M2" stamp on the bumper?  My understanding is that the first number (4) stands for 1964; the second number ( remains a mystery to me; and the final digits (M2) represents December 2.  In other words, excluding the 8, it translates to December 2, 1964.  Thanks, Ron

[jwc66k]

But how do we interpret the "4  8  M2" stamp on the bumper?  My understanding is that the first number (4) stands for 1964; the second number ( remains a mystery to me; and the final digits (M2) represents December 2.  In other words, excluding the 8, it translates to December 2, 1964. 

The "4" is month, the "8" is the day, "M2" is the manufacturer's ID and shift. My Oct 18, 1965 (scheduled) build San Jose original (re-chromed but with a new scratch) bumper is marked "10 11 #$" (can't make it out).
Jim

[CharlesTurner]

Bumper date codes are a bit cryptic.  Normally it is day, month and then the model year.  Here is an example of an assembly line date code:

http://2.bp.blogspot.com/-_Ato132WsnU/T01acahtoMI/AAAAAAAAjv0/F2oM8UPzGJg/s1600/IMG_2482.JPG

5 13 M4  (Note the M in M4 is most likely the plant, but the next number we have seen it correlating to the 'production year' and not the actual year of manufacture). 

So, 5 13 M4 would be May 13th, model year 1964. 

The reason I believe the last number is the model year is based off examples of original/unrestored cars.  As an example, I have seen dates like 10 12 M6 on an original '66 car, which if you take this directly, would decode to October 12th, 1966.  But that wouldn't be possible on an early '66 car as they were being made in 1965.

As for your 4 8 M2, it doesn't fit within the normal production time period and I would just interpret it as the year the replacement part was made, which most likely was 1972.  Later Ford bumpers changed to an 'A 65' or similar format, which is nothing like originals.  Most likely done as it was part of the specifications, but it's really irrelevant if it's made in the 1990's.  The early tooling most likely wore out or maybe sold to another company that changed the format.

[MustangAndFairlane1867]

Many thanks everyone for the feedback to my "mystery" bumper post.  When considering what Charles and others said, I have to conclude that this bumper is basically scrap at this point, especially considering that vendors such as NPD have nicely-chromed after market bumpers at a fraction of the cost of re-chroming an old one.  If this were the car's original bumper, then I might look into restoring it, cost be damned, but not in this instance where the numbers (and paper tag) clearly indicate it was not original to my fastback or any other Mustang.  Thanks, Ron

[CharlesTurner]

If it's a good straight bumper with no rust, it might still be useful.  The date could possibly be modified to fit the assembly date of your car and then re-chrome.

OEM bumpers are much better quality than repro in my opinion.  Some are different in bends/cuts also, so don't assume that a repro will match exactly.

[jwc66k]

If it's a good straight bumper with no rust, it might still be useful.  The date could possibly be modified to fit the assembly date of your car and then re-chrome.

Difficult to do on a metal stamping.

OEM bumpers are much better quality than repro in my opinion. 

That's true, not opinion. Cut my hand on the edge of a repro bumper.
Jim

[jwc66k]

My Oct 18, 1965 (scheduled) build San Jose original (re-chromed but with a new scratch) bumper is marked "10 11 #$" (can't make it out).

I took a closer look at that bumper and there's a very faint "M6" at the end of the "10 11".
On another 66 Mustang that I've had for almost 29 years, the bumper was swapped to another 66 Mustang that I was selling that needed a "better looking" bumper. The one currently is marked "12 23 M6". The car it came from was a mid-January 66 build. The coding is within the range of a January 66 Build. The "M" I believe is the manufacturer's ID, the 6, or any other number, may be almost anything, stamping machine, inspector, who done it - but as a "6", not a shift.
Jim

[C6ZZGT]

Many thanks everyone for the feedback to my "mystery" bumper post.  When considering what Charles and others said, I have to conclude that this bumper is basically scrap at this point, especially considering that vendors such as NPD have nicely-chromed after market bumpers at a fraction of the cost of re-chroming an old one.  If this were the car's original bumper, then I might look into restoring it, cost be damned, but not in this instance where the numbers (and paper tag) clearly indicate it was not original to my fastback or any other Mustang.  Thanks, Ron

I would rather have this bumper than ANY repo bumper !

[J_Speegle]

Thanks for the info on the replacement part information.  Makes sense.  But how do we interpret the "4  8  M2" stamp on the bumper? 

For dating there is a article in the library posted in each year section (Blue highlighted sections at the top of the first page)  labeled - Date Codes - Decoding Date Codes



M is the stamping plant - Monroe

Should help with many similar questions for you and others

[CharlesTurner]

The "M" I believe is the manufacturer's ID, the 6, or any other number, may be almost anything, stamping machine, inspector, who done it - but as a "6", not a shift.
Jim

Did you read my post above?  The number past the M is not a 'shift' or 'almost anything'.  It is very consistent that it matches to the 'model year' for the car, not the year the bumper was made.  In other words, it would be expected that just about any '66 Mustang would be 'M6', no matter if the car was made in Fall of '65 or later in '66.