VIN differences between M1008 and M1028?

[Michael]

This info is found in Section OA-2, general information in any GM service Maunual.

I looked in my copy of a 1980 and 1998 GM service manual and both have a full page on decoding vin numbers. Unfortunately neither are close enough in time to be of much help with CUCV's. The 1998 did have D= military 4/4 for the 5th digit. I was thinking that D might just mean government based on the first post in this thread.

Here is what I have so far, I hate to say it is final without looking at the info from a 84 to 86 GM service manual, but so far I have not been able to find one.

1st digit = country
-- 1 = USA

2nd digit = company
-- G = General Motors

3rd digit = division
-- B = Chevrolet, incomplete example contract maintenance trucks
-- C = Chevy Truck
-- 8 = ? All M1009's (blazers)

4th digit = GVWR/Brake System
-- E = 6001 - 7000 Hydraulic
-- F = 7001 - 8000
-- G = 8001 - 9000
-- H = 9001 - 10000

5th digit = Line Description & Chassis Type
-- C = 2 Wheel Drive 1981-86
-- K = 4 Wheel Drive 1981-86
-- D = military 4/4

6th digit = Series
-- 1 = 1/2 ton
-- 2 = 3/4 ton
-- 3 = 1 ton

7th digit = Body Type
-- 4 = 2 Door Cab
-- 8 = Blazer

8th digit = Engine Description
-- J = 6.2L V8 Diesel

9th digit = character is a check digit to verify VIN accuracy using a mathematical formula

10th digit = Model Year
-- B = 1981 F = 1985
-- C = 1982 G = 1986
-- D = 1983 H = 1987
-- E = 1984

11th digit = assembly plant
-- F = Flint

Vin model year may not match the trucks model year
Some trucks listed as 1986 have an H model year code.

 

[GM72K10]

I have an 85 C/K service manual and an 88 R/V/G/P manual. they are very similar to above:
First digit, Nation of Origin 1= US 2=Canadian 3= Mexican
Second Mfr, G= General Motors
Third, Make, B= Chevy incomplete (M1031) C=Chevrolet Truck (p/us, blazers)
Four, GVW, G 8001-9000, H 9001- 10,000 etc
Five, Line and Chassis R,C =Conventional 4x2
K,V =conventional 4x4
D= Military Truck 4x4
Six, Series 1=1/2 ton, 2= 3/4 ton, 3= 1 ton
Seven, body type, 8= Utility (Blazer, Jimmy)
4= 2 door cab
Eight J= 6.2 Diesel RPO LL4
Nine Check Digit
Ten , Year J=88
H=87
G=86
F=85
E=84
D=83
Eleven, assembly plant, F=Flint

 

[Michael]

So you are saying that the factory service manual does not define an 8 in the third digit but does define D as military in the 5th digit. I always assumed that it was the D in the 5th digit that was making the vins come back as invalid since they are not on any of the Internet sites that I have seen. I have looked at about 20 M1009's on GL as well as the ones I personally own and they all have an 8 in the third digit. It was a M1009 that I personally had trouble with.

 

[CUCVFAN]

From 1981 to 1986, the 3rd character of the VIN was either of the following:
A = Chev (10 or more passenger)
B = Chev Tr., Incomplete Vehicle
C = Chev Tr., Complete Vehicle
8 = Chev Tr., Multipurpose Vehicle

In 1987, the "8" became an "N", just as the"K" for a civilian 4x4 became a "V" ( military models remained a "D").

So, Blazers and Subs from 81 to 86 have an "8", to indicate they are SUVs, or "multi-purpose vehicles". Given that I believe there were no 1987 M1009's produced, I would say every M1009 has a VIN that starts with 1G8ED.

BTW, NEVER believe any VIN on the GL website. Always verify it yourself. I've seen many times where a M1008/M0128 is listed with the VIN of a M1009 or vice-versa.

 

[Michael]

BTW, NEVER believe any VIN on the GL website. Always verify it yourself. I've seen many times where a M1008/M0128 is listed with the VIN of a M1009 or vice-versa.

You can't trust what they put on paper either including the form 97.. That is one reason I am being so persistent with this. With all of the CUCV's being released from Gl without doors and windshields it is not uncommon to find trucks with VIN tags that are hard to read due to rust. When I started all of this I didn't realize that there was a full page in the service manual covering this. I just bought a service manual on ebay, when it comes in I will post a final version with documentation in a new post.

 

[Kremlin]

CUCVFAN (Or anyone), talk to me about these RPO codes please, really old thread here I know, but I don't find much on RPO code decoding after an admittedly quick google and SS thread search...I know I've got an "H" code as 4th digit in the VIN on my newly acquired CUCV, so I know it's one of the M1028 or M1031s but the bed has been removed and converted to a flatbed with an EZ Dumper dump bed insert (12v electric over hydraulic not PTO) by the USACE so trying to figure out what underlying equipment I may have or originally had. I can inspect underneath next I'm near it to see if it has the P208 or NP205 later; but how can I tell if it has/originally had the 100 amp/28 v communications kit? It does have large multi-pin commo plug in the cab still...?