VIn# on rolling frame matches nothing

[cadillac_al]

This VIN is very easy to read and the frame is very clean but the Letters and numbers don't match any VIN decoding instructions that I can find. It does start with a C. It is C5B10835. Does anybody understand this? TIA

[old Rusty C10]

that may be a part number i remember the 10835 being on a frame i had here for a while on one of the many trucks i had

[Keith Seymore]

Yah - that might be a part number and date code, especially if it is on the side of the rail.

The partial VIN will be on the top surface of the top horizonal flange.

K

[Keith Seymore]

It's one digit short of being a partial. Make sure there's not a "1" hiding in there somewhere.

Then it would be "C5B108351", for example, where

C = Chevy
5 = 1985 model year
B = Baltimore final assembly
108351 = sequential portion (aka serial portion) of VIN

K

[cadillac_al]

Thanks Keith, I figured it out from one of your previous posts. When you were explaining about wrestling a large stamping machine to stamp the numbers, you said you just stamped the make, year, assembly plant and sequential serial number. I figure this is why they call it a partial VIN/serial number. The weight rating and drive train and body type can be added to the VIN/serial number later. There is a mark that looks like they tried to stamp another number but only got the very top of the number, like the top of an 8 or 6 or 9 or 0 something with a slight curve on the top.

I assume the frames got stamped before the axles and engine were installed?

[Keith Seymore]

Originally Posted by cadillac_al

Thanks Keith, I figured it out from one of your previous posts. When you were explaining about wrestling a large stamping machine to stamp the numbers, you said you just stamped the make, year, assembly plant and sequential serial number. I figure this is why they call it a partial VIN/serial number. The weight rating and drive train and body type can be added to the VIN/serial number later. There is a mark that looks like they tried to stamp another number but only got the very top of the number, like the top of an 8 or 6 or 9 or 0 something with a slight curve on the top.

I assume the frames got stamped before the axles and engine were installed?

After axles but before engine set.

The frame starts out upside down. The axles/suspension are set in place while the frame is upside down. After they are secured the frame is flipped right side up using a chain hoist.

Once it's rightside up the brake and fuel lines are added along the rail and the VIN stamped. Engine set comes later and then on to body drop.

https://www.73-87.com/7387info/Assembly%20Line.htm

K

[Keith Seymore]

Originally Posted by cadillac_al

I figure this is why they call it a partial VIN/serial number. The weight rating and drive train and body type can be added to the VIN/serial number later.

Actually - the full VIN is established well before the build starts. That's why it can appear on all the build documentation (build sheet, inspection tickets and such) and be broadcast throughout the whole plant.

They just chose to stamp the partial VIN on the frame, rather than the full VIN, for whatever reason.

K

[cadillac_al]

This rolling frame is a hodge podge of parts that had me confused for a while. It was advertised as an 80's frame and the front frame horns were cut off diagonally like an 80's frame. It has a 14 bolt semi float rear and corporate 10 bolt front axle. It also has a 700r4 and an aluminum transfer case and a drivers side gas tank with an internal fuel pump. Everything about it said 80's until I got to the partial VIN on the frame. Then I noticed that the front frame horns had been cut with a torch. Then the research began and I kept stumbling on Keith's posts until I figured it out. It has to be the cleanest 75 frame within 1000 miles anyway.