How to read find use part numbers and the MPCs

[Dan Szwarc]

I'm starting this thread because it was mentioned and I'll quote a post I made years ago:

First, you gave me the part number: D4VY-15A440-B
The 15A440 is what is known as the base part number. I opened up the 73-79 MPC Part 1 file (that's also known as the "parts list" catalog (the other one is the illustration catalog - ie. pictures) and jumped to Section 150.

Why section 150? Because the base part number is 15A440, right? Ignore the A (Ford throws letters in the middle of PNs for some reason) and just look at the 15440. The first three digits tell you what section to start in: 154. Since there is a section 150 and a section 160, it must be in section 150.

(If it was PN 9660, I would have gone to section 90 (first two digits). In other words, ignore the last two digits to start.)

Back to PN 15A440: Scanning through Section 150, it starts with 15000, which is a CLOCK ASSY. I scan down until I get near 15440 and start to look for the A in the middle. 15A440 comes right after 15B439 because 440 comes after 439 (remember to ignore the letter).

15A440 is the BEZEL (FRONT OR REAR SIDE LAMP). Now I look for model "D" (in the second column), which is for a Continental and check the third column for the full PN. I find it and look to the left in the first column for the model year.
It says 74/. This means 74 and up to the max year of the MPC (which is 1979).

Therefore D4VY-15A440-B is used from 1974 through 1979.

There's much more. Like when a PN seems to have too many digits or Starts with C-. I welcome others input.

[action]

Usually the letter in the middle of a base part number is because they ran out of base numbers in that grouping.
And know that some base part numbers have been reserved for the future and created in the design or initial engineering phase. That base number may or may not make it to final production. But will be set aside for future use for a period of time.

So in the world of 150xx low to 150xx to high there are 99 possibilities. Unless a letter was introduced. Which increases availability.

The numbering system goes back to pre-war.
No one then had any idea about emission parts, electronic parts or?
And the future with electric power plants may be interesting as to numbering. Or maybe that has already been figured out.

I could swipe a few tables on other websites. Just not sure if that is right to do.

>>>Action

[LithiumCobalt]

Another thing to potentially muddy the waters is the distinction between part numbers and engineering numbers, which makes this whole topic even more confusing. I’m not sure when the engineering numbering nonsense started, but a lot of times more modern parts will have the engineering numbers stamped on them as opposed to the true part number. I have no idea if there is a reference catalog that ties these to true part numbers or not. Maybe it is irrelevant for our discussion as this is a site dedicated to a time before this practice seemed to occur with parts, but something to be aware of.

[action]

I am not aware that Ford EVER used part numbers on parts. With a couple of exceptions like carburetors.

I have seen engineering numbers on production line parts from the 1950s to the present. Some times the part has a paper tag with the engineering number on the tag. (wire harnesses) And most of the time the engineering number (or parts of the engineering number) are ink stamped or cast into the part.
A little off topic, Partial VINs were ink stamped

And Ford Motor Company is the only company in this industry or any industry that I am aware or that does this type of numbering

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[Mike]

It's not worth getting into engineering numbers. i don't think that even comes to play with the older cars.
The biggest confusion is how the service manual only shows either the group number or base number which is usually meaningless unless you have the parts catalog to figure out the actual part number from it.

[action]

It's not worth getting into engineering numbers. i don't think that even comes to play with the older cars.
The biggest confusion is how the service manual only shows either the group number or base number which is usually meaningless unless you have the parts catalog to figure out the actual part number from it.

That is the point. The shop manuals are not written for anyone other than a service tech at a Ford store. Non-Ford service stores use them, retail customers use them. Now hobby people use the shop manuals but the manuals were not written for us. They were written for the Ford tech at a Ford store with the Ford MPC. Because suffixes can change during the course of a model year, having a suffix in the shop manual would mostly be wrong. The prefix which doesn't change much is specific to a vehicle line and model year. Which the tech knows.

The tech knows what he is working on.
And the tech knows the type of part is wanted.
The back parts counter guy knows basic part numbers to get to the section in the MPC to look up the part.
It makes the job faster, easier and more accurate if the base part number is known. That isn't always possible.
BTW before the base parts numbers were in shop manuals the dealership techs made that request to put base numbers in the shop manuals.
It cost the company more labor to add that data. But the net effect was positive.

If the tech says I want a clock adjustment knob and the tech knows it is a -15032- because he got it out of the shop manual. He can tell the back counter parts guy he needs a -15032- clock knob for a 1967 Lincoln. The communication would be clearer than without the base part number from the shop manual. If the back parts guy ordered a whole clock when only a knob was needed because of a mistake that would be not a good thing. Most of this communication is written but it is hand written. A number is far easier than letters.

Sadly base part numbers have not always been in shop manuals. And there are errors in the shop manuals as well.

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[Dan Szwarc]

Ok, some tips.

None of the part numbers are real (I Just made them up).

The typical ford part number is C8VY-8001-A or C8VY-20505-A

The 8001 and 20505 is known as the base part number. Base part numbers are usually 4 or or digits.

If 8001 is for a radiator, then for all ford vehicles, the radiator will have the same base part number of 8001.

The C8VY is known as the prefix. It tells us the decade, year the part was released or first used, vehicle line (like Ford, Mercury, Lincoln), and maybe area of application (that part varies). The breakdown for this is easily found on the internet.

The A is the suffix. Sometimes it is used for design revisions (B might replace A) and sometimes for completely different designs (A might be a two-speed wiper switch and B might be the variable speed).

The fun part come in for a lot of body parts. If you ever see a part number with 7 digits, you have the be careful.

The part number for an armrest might be D0AB-6324144-A. The base part number is 24144, not 6324144.
The 63 is a body code. Ford put the body code in front of the base part number. Back in the days of sedans, coupe, convertible, and four door hardtops, there were lots of body codes at Ford. And sometimes a Ford coupe might have a different body code than a Lincoln coupe (if they were based off of different core or chassis designs - long story).

There are numerous varying body codes across the 60s and 70s. 63 might be for a coupe if it is a mercury.
74 would be a convertible 60s Lincoln. If this was a Lincoln part, it would be D0VY-7424144-A. I add a space when typing it out for clarity, D0VY-74 24144-A. No hyphen.

To find a part number like this in the MPC, you have to look in the correct section starting with 24144, then carefully find where the 63 (and 62, 74, etc.) parts are listed in that section.

There are other general rules like even part numbers are for one side of the car and odd are for the other side, but only generally. If a part is the only one of its type (not LH or RH), then the rule won’t apply no matter what side it is on (like a steering wheel).

When a letter appears inside the base part number, that’s for something found near, around, or similar the base part number, but unique for some reason.

If a base PN for a piece of trim like a grille is 8522, but the car has a split grille or a unique bezel, ornament, or whatever, then the oddball part might get a letter stuck in before the last three digits, like 8B522. To find it in the MPC, You look in the 8522 section and 8B522 will be after 8522 and before 8523. Similar for a 5-digit number with a letter stuck inside (24144 might become 24B144 and 7424144 would be 7424B144).

Ford only updates parts if they are special to a car. One might find a ford part on a Lincoln (D2AZ is a full-size Ford prefix and might be found on a Lincoln from 1972 or 1973).

You may find parts with old part numbers on newer cars. That’s just carry-over.

If you ever find a newer part number, like a 1975 D5AZ part on a 73 Lincoln, that’s means the part was replaced with a service part number that was improved or released years later. Ford alway uses the service part numbers in their MPCs if they existed at the time of publishing.

A water pump on a 75 Lincoln with a 460 might Originally be a D3AZ part number, but in 1978, a D8 part replaced it. All you will ever find are D8 parts for sale. Ford stops making the old part as soon as a redesigned part is made available because they know they interchange.


That’s what I have for now.

[CaptainDave]

OMG, my head is swimming! But over time, this will prove very helpful. Thanks to all who commented so far, and to those who will continue to add to this.

[Dan Szwarc]

I am not aware that Ford EVER used part numbers on parts. With a couple of exceptions like carburetors.
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What? Dave, you’re crazy! Ford put parts numbers on many things. Molded into that backs of chrome grilles, the inside of body trim plastics, on the sides on switches, on harness tags, etc. there’s part numbers everywhere!

Things that get machined and have secondary manufacturing operations like engine blocks, cranks, intake manifolds, get engineering numbers because it’s not the final part until the final process is completed. That is a whole ‘nother ball of wax.

Carbs get tags because there’s hundreds of combinations of other parts that go in them to be used in the final assembly application. And sometimes their pieces are mixed and matched (like tops and bottoms).

Partial VINs? Let me tell you about partial VINs...

Can you name the two places a partial VIN is mechanically stamped onto a typical 66 Lincoln?

[action]

The numbers on production parts are engineering numbers.
Or partial number of base numbers
They may appear to be part numbers as they follow the same format Prefix-base-suffix

For the attached

There may be part numbers on service replacement parts as a tag
This head light door has the part number of C6MY 13064 A
Cast into the back side near the top is TOP RH C6MB-130 52-A1

When there are left and right parts of the same description (Head light door) typically (just not always which is frustrating) the right side has a even base number and the left side has an odd base number. The other variation to this is to change the suffix with A or B instead of changing the base number.

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[Dan Szwarc]

I think this may apply to parts requiring secondary processing operations, like castings and stampings.

I've seen proper PNs on many parts.

It is important to know that what one sees isn't necessarily what one gets. I know it's tripped me up many time.

Thanks, Dave.