[The Lime Crime]

Did each assembly plant have an assigned set of numbers or would they all start from 0.
I am asking if: one came from Baltimore and on from Arlington is there any possibility that the serial digits would be duplicated and the only difference be the B (Baltimore) or R (Arlington)?
Yes, I have a reason for asking, but let`s keep it simple for now.
Could there be a:
1GTCW80H9DB500592 (and a)
1GTCW80H9DR500592?
Thanks,
JP

 

[Chris Nelson]

1=USA, G=General Motors, T= ?? should be a 1 or C, C=4001-5000 pounds GVW, W=El Camino, 80= 2dr. pick up , H= 305 V8 - 4 barrel carb, 9= Check didgit, D= 1983, B= Baltimore plant , R=Arlington plant , 500592= production # . Is that B really an R ? or visa versa ? I think each plant has a # like starting with 100001 would be 1st car made that year . Since yours is 500592 yours was the 592 made that year at plant 5 .So no is my answer . you need to check your #s again . This is my guess but not 100% sure . If you let me know ahead of time what year your car is it would be a lot easier . If you post your cowl tag I can give you more info .

 

[The Lime Crime]

It has an R on the VIN plate, but somehow over the years the title became a B. They are both valid plant codes. I don`t know what you mean by "made that year at plant 5" when the plant codes are letters? I have no question about the deciphering, my question: can there be a 500592 from both Baltimore (B) and Arlington (R)? And the T designates truck.
They both, theoretically can be valid numbers unless the plants were working from different number groups. I found the remnants of a build sheet that indicated the car was delivered to Lodi, CA, which seems logical for a car built in Texas. The build sheet literally disintegrated. It is a Caballero not an EL Camino.
I have never had success with posting photos on this site but the VIN is 1GTCW80H9DR500592 on the cowl tag.
JP

 

[87next2last1]

3rd digit T = GMC Truck
I say typo error on the title
My title has a typo error on it (my 87 has a 2 for the first digit on title but VIN is a 3)

 

[The Lime Crime]

It can be a problem if you want to sell.
So, you don`t think there would be a 500592 number on 2 cars from 2 plants? That is my only question.

 

[Karadjgne]

No, there wouldn't be the same consecutive serial numbers from 2 plants. Afaik, the numbers assigned to different plants were in ranges, Arlington might have had 1-3000, Baltimore would have 3001-5000 for instance. All assigned by GM Corporate for expected production amounts, done several times a year. But thats also older, as the later year 5th gens GMC were all made in 1 plant in Mexico as US plants were being retooled for the S-10. It explains why actual production numbers don't lineup with serial numbers, there'll be blocks of serial numbers missing if numbers were assigned but the quota per plant wasn't met.
1GTCW80H9DR500592 would be an 83 Caballero.
1. US
G. GM
T. GMC Truck
C. Hydraulic Brakes
W. El Camino/Caballero
80. 2 door sedan pickup
H. V8, 305 CID
9. Check digit (using this can figure out if it's supposed to be a B or R plant)
D. 1983
R/B. Plant
Rest is sequential serial numbers.

But that doesn't add up correctly. If the plant was B, the check digit would be 4, if the plant was R, the check digit would be 5.

According to the check digit of 9, the vin should read 1GTCW80H9DD500592 made in Doraville, GA.

 

[The Lime Crime]

I am quite sure of the digits and letters on the VIN tag the check digit is 9, D for 1983 then an R so apparently the car is impossible. Why would there be different check digits for different plants? Seems every answer just raises new questions.

 

[Karadjgne]

A check digit is a semi-random ISO standard number 0-9 or X (10). What happens is you change the letters for numbers, add everything up then divide by 11. The check digit is the remainder. It's a computer verifiable identifier. If you had 1GTCW80H9DD500592, but the car was an 84, it'd read 1 number more than that or 1GTCW80HXED500592, the E being 84 so changing the remainder of 9 to 10 (X).

So if absolutely positive about all letters and numbers except the plant letter, it has to be a D as B, R, K, Z, 1 plants add upto a different remainder, usually 4 or 5 for the check digit. With a 9, the only plant that fits (all other vin letters correct) is D with check digit 9.

So if absolutely positive the plant is B or R, and check digit is 9, and it's D for 83, then one of the other numbers/letters is incorrect. That's the purpose of the check digit, an identifier, all the others have to add up and divide by 11 for it to be correct. It's not different check digits for different plants, it's different check digits according to the total of all the letters/numbers.

According to the DOT vin check digit calculator, there's only 2 possible vins that match up.
1GTCW80H9BR500592 which makes the car an 81 not an 83, or 1GTCW80H9DD500592 for an 83

 

[The Lime Crime]

So, once again, you are telling me the car can not exist. I think I will try a title service.

 

[Old Bear]

Does someone else have a known good vin that @Karadjgne could run through the algorithm for the check digit.
That might help validate that it is using modulus 11 rather than a different one.
It might also indicate if not all of the VIN characters (excluding the check number) were used in the algorithm.

 

[Karadjgne]

I ran mine. It's good.
3GTCW80HXHS800499. The check digit is X, 10.

Check Digit Calculator

vpic.nhtsa.dot.gov

If you use this one, with a ? in place of the check digit, and plug in all other characters, it'll tell you what the check digit is supposed to be.

Check Digit Calculator | CJ Pony Parts

The 9th digit of a Vehicle Identification Number, or VIN, is the "Check Digit" and is is used to validate the VIN. Use this calculator to see if your VIN is valid.

www.cjponyparts.com

I ran several different vins, exchanging 5 for 8 and D, R, B etc and only 2 came back as valid with 9 as the check digit, cross checked with the DOT. That was the 1GTCW80H9BR500592 which makes the car an 81 not an 83, or 1GTCW80H9DD500592 for an 83.

 

[The Lime Crime]

I just ran and printed out sheets from the NHTSA/DOT link and it says 1GTCW80H9DR500592, Error Text 0 VIN decoded clean. Check Digit (9th position) is correct. The title(with B, not R) showed error.
Next step is see what my local title folks have to say, that is all that counts anyway.

 

[Karadjgne]

Dunno what's. 1GTCW80H9DR500592 is not a valid vin. 1GTCW80H9BR500592 is, as is 1GTCW80H9DD500592.
To me, it looks like way back on the day, before the DOT was really hooked up nationwide with the net, somebody did something shady with the title/vin, and as it's passed hands, down the years, it's rang up as good/not stolen/salvaged as it has the right amount of numbers and is already in the system as good/not stolen/salvaged. Nobody ever bothered to check the vin itself, just the history.

It wouldn't surprise me in the slightest if the car was in reality an 81 with 1GTCW80H9BR500592, stolen, the B carefully changed to a D and filed for lost title with a fake bill of sale. Back then that wasn't all that hard to do, it was all hard copy paperwork, but end result is a clean, non-stolen 83 instead of a stolen 81 Camino.

 

[The Lime Crime]

 

[The Lime Crime]

They look much more clear in person

 

[Karadjgne]

That Vin is in the system. Has been. So it's going to come back as valid as far as the actual history is concerned.

What's not valid is the Vin itself. The check digit according to all US government regulations comes back as it should be a 5, not a 9.

So what you have is one of 2 things as far as I can tell. 1) it's a chop-shop vin tag on a fake vin, stuck into the system from way back when the car was basically new, creating a valid paper trail or 2) it really IS a valid vin and you have a $1 million dollar factory OEM mistake (they do exist, Graveyard Cars verified a Dodge with such) making it a 1 of 1.

That particular vin should not exist. The check digits are there specifically to prevent such. Where you go from here is upto you, you could let it ride and enjoy your car, or contact GM and get to the bottom of things.

There may also be a vin stamped into the top of the frame on the passenger side just in front of the wheel well, but you'd need to pull the body off to access that. I know California uses the frame vin as final legal, not the dash vin as dash is easy to replace but few keep the body while replacing frame. If frame number matches the dash, I'd say you got a factory OEM mistake that's not supposed to exist.

 

[The Lime Crime]

I have an appointment with my Texas title people(Harris County) where I registered it. If they change the title to match the VIN then the next step is a BIG For Sale sign!

 

[The Lime Crime]

From GM archives via Allied Vaughn

 

[The Lime Crime]

Oh, when I spoke with him he said he had not researched the check number. I have e mailed since opening email tonight and hope they may clarify for me a little. As you can see, the VIN tracked to an invoice to Plummer Pontiac Cadillac GM in Lodi, California, consistent with the remnant of build sheet I found. I will note, when I used the option on the NHTSA and manually entered the model year, it came back valid.
Oh, the mysteries of life!
JP