Frame VIN Derivative

[Kevin Whiteley]

For 68 model year at least, at what point during the build process was the frame VIN derivative stamped onto the frame? I'm guessing that it obviously had to be before body drop, but was it well before or immediately prior to body drop so the "stamper" read it off of the "official" VIN.

And since were on the topic of VIN derivative stamping, when was the transmission stamped?

[Michael H.]

Re: Frame VIN Derivative

Kevin,

The frame numbers were done about half way down the chassis line, just before the engine and transmission were installed in the chassis but after all of the suspension was in place. The chassis numbers were put in with a large air operated stamp press, unlike the engine/transmission numbers which used a small hand held tool that was hit with a large hammer.

The transmission and engine VIN stamps were both done at the same station on the engine dress line. The engine and transmission were already bolted together at this time.

Note of interest: There were a lot of chassis that went through that were actually hand stamped one character at a time instead of the typical gang of characters used with the air operated tool. If you ever see one with obvious variations from "typical production", it could be genuine. The characters will be randomly placed and most likely, a different style than those characters used with the air operated tool.

Michael

[Kevin Whiteley]

Re: Frame VIN Derivative

Michael,

I guess this is where the job number comes into play. The plant knew that body job number "xyz" had VIN "123", so frame assembly "xyz" would get stamped with VIN derivative "123". Am I correct in assuming that the body assembly already had the VIN tag attached to the windshield area (for C3's)?

[Michael H.]

Re: Frame VIN Derivative

Kevin,

Yes, the job number was already known and posted/applied to the chassis when it was still in the stack of frames, ready to be placed on the first position on the frame conveyor/line. The same is true for the body and it's "job number". One of the very first things that was done to both the frame and body floor pan was the addition of these "job numbers" as the entire rest of the process relied on this number for information for it's build. Broadcast sheets for each car were floating all around that plant as the car went through it's build. The chassis line had several, the body line and engine dress line all had copies. The cars were never refered too by VIN or serial number but by job number until the end of final assy. The job number, with a max of three characters, was a lot easier for the workers to use than a multi character VIN.

I don't remember exactly where in the process the VIN and trim tags were installed on C3 and later but the tags for C2 were stamped and installed just after the final body paint operation. I think C3 was the same but not 100% sure.

[Tom R.]

Re: Frame VIN Derivative

It changed! C3 VIN and trim tags were installed as Michael indicates once the body shell was ready for trim as was done during C2. In the mid-70's, best guess 75-76, the station moved between paint booth 1 and paint booth 2 or the paint repair station. The evidence is revealed with trim tags painted body color...but no primer. Yet...all have body color under the trim tag. Consequently, the paint peels off relatively easily from the stainless steel tag for post-75 tags. VIN tags were installed at the same and if body paint got on the VIN...well the black out process covered the sins of overspray.

This was done because as the volume of production increased during the 70s, more space had to arranged in the plant for trim line tasks. Production increased from 6 units per hour to 10 units per hour during the early 70s.

[Michael H.]

Re: Frame VIN Derivative

Kevin,

I'll try to post a few pictures of the frame job numbers being applied while the frame was still in the stack just inside the back door of the plant. There was a worker that walked around the piles of frames, stack of broadcast sheets in hand, writing the numbers on each frame.

The very same is true for the body floor pan. The job number was written on the panel before anything else was attached to it.

Each car had it's destiny carved in stone before it even began life on the line. Bodies were frame specific and frames body specific long before they even started production. I know it's been said here on this board in the past that this was not the case but I can 100% guarantee that it was. Nothing was randomly selected and each body already had a specific frame assigned to it long before either were going down the line.

I'm a little surprised that no one asked about the occasional "hand stamped" frame VIN numbers. Is this already common knowledge?

Michael

[John H.]

Re: Frame VIN Derivative

Michael -

My group supplied the George T. Schmidt air-operated "egg-stamper" that was used on the Chassis Line for the VIN derivative; same basic device that was used in the passenger and truck plants, with unique hard-point locators for each car line. Have tried to get photos recently from Schmidt, but nobody who works there now even remembers them - they're into high-speed laser marking equipment these days

[Michael H.]

Re: Frame VIN Derivative

John,'

I'm 99% sure I have a great shot of the unit in actual operation at the Corv. plant. I'll look and, is so, I'll post it. I also have a GREAT shot of the numbers being put in by hand with what looks like a typical hardware store number set.