View Full Version : engine and trans pad stamps
black69
11-20-2015, 07:05 PM
Did GM use the same stamp for the trans as they did for the VIN on the engine?
I am assuming they did, like mopar, but had to ask.
I recently noticed a difference on a post 1970 car that made me wonder.
black69
11-20-2015, 11:07 PM
thanks. I recently got confused when I saw the 1's characters on a survivor car, block vs trans. The 1s on the trans looked more like vertical lines. thanks.
Stefano
11-23-2015, 06:18 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mr70</div><div class="ubbcode-body">Yes Chevrolet did. </div></div>
Yes, generally they did. But with so many plants and models, there have been anomalies found.
black69
11-24-2015, 01:25 PM
Hi Stephano, now that you responded, when I looked at the 74 454 vette you had listed forsale, it was the trans stamp that made me wonder about the top of the 1's. It sure looks like it was the same stamp on everything else. Thanks!
Day2_69Z
11-24-2015, 02:46 PM
Here are Examples of Factory Stampings.
First is the Original Muncie , late build,
10 C & 661 case with drain and fill.
69 Z/28. M 21.
the '777' vin stamp is Actually *111*
Second is an NOS 302 Engine Assembly
From the Flint Michigan engine plant.
Note Date # 7 & letter capital I in lieu
of 71
Day2_69Z
11-24-2015, 03:58 PM
http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-13370-34744-temp_4.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-13370-34745-temp_3.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-13370-34746-img_20150616_013117.jpg
70 copo
11-24-2015, 04:43 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: black69</div><div class="ubbcode-body">Did GM use the same stamp for the trans as they did for the VIN on the engine?
I am assuming they did, like mopar, but had to ask.
I recently noticed a difference on a post 1970 car that made me wonder.
</div></div>
Yes.... and there were anomalies that were related to the production process as well.
black69
11-24-2015, 04:47 PM
I understand the character substitutions mentioned (7 for a 1 in the one example, and I for a 1 in the other example). But shouldn't the substitutions of characters be same on block and trans if using the same stamp?
70 copo
11-24-2015, 04:53 PM
Yes, unless the engine or transmission was replaced as part of an in plant repair at AGR. Then another set of stamps could have been used along with alternate stamping locations.
black69
11-24-2015, 05:25 PM
Now that was helpful! That I can understand on how they could be different.
thanks!
Stefano
11-24-2015, 06:36 PM
I would say the stamps on my former Corvette were the same characters.
http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-295-34762-dscn1419_2.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-295-34763-dscn1401.jpg
On '67 Corvettes they didn't use the same holder. They forgot to advance the number when they hit the transmission on my '67. The build date of the transmission matches the Warranty Plate and engine and transmission have never been out of the car.
black69
11-24-2015, 08:35 PM
Sorry Stephano, I was working from this picture that you posted. For some reason that detail did not show up.
That other picture is better.
http://i358.photobucket.com/albums/oo29/xxxblack69/full-295-29755-dscn1418_zpsnpetvbmu.jpg (http://s358.photobucket.com/user/xxxblack69/media/full-295-29755-dscn1418_zpsnpetvbmu.jpg.html)
fiveforty
11-26-2015, 01:53 PM
How is this for an 9L526889 69 Z28. What happened there? http://www.yenko.net/ubbthreads/pics/usergals/2015/11/full-4703-35111-007.jpg
ZLP955
11-27-2015, 05:24 AM
The stamp on the Muncie case may appear a little different because the softer aluminum (versus the cast iron of the block) allows a deeper impression.
Keith Seymore
11-30-2015, 01:16 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TimG</div><div class="ubbcode-body">On '67 Corvettes they didn't use the same holder. They forgot to advance the number when they hit the transmission on my '67. The build date of the transmission matches the Warranty Plate and engine and transmission have never been out of the car. </div></div>
Love it.
Ten years ago I would have sworn up and down that we never let any of these out because we were so diligent to check and repair on the line.
Now - I've seen literally hundreds of assembly line mistakes relative to VINs (mostly trucks). I never would have believed it.
K
jeffschevelle
12-01-2015, 11:23 PM
67 and prior Chevelles did NOT get the same stamp dies on the trans and the engine. A couple of the plants had gotten more uniform by the end of 67 production with the use of gang holders, but even then the dies in the two stamps were not always the same. I cannot speak for 68 and later, but there is no question about it for 67 and prior.
black69
12-01-2015, 11:37 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jeffschevelle</div><div class="ubbcode-body">67 and prior Chevelles did NOT get the same stamp dies on the trans and the engine. A couple of the plants had gotten more uniform by the end of 67 production with the use of gang holders, but even then the dies in the two stamps were not always the same. I cannot speak for 68 and later, but there is no question about it for 67 and prior. </div></div>
That is some great knowledge to learn! The restoration shop that worked on my cuda specialized in the 66-67 chevelle area. I cant wait to ask them about the stamps on the cars they have done and the ones they are doing (engine vs trans) <<GRAEMLIN_URL>>/smile.gif
camaromb
12-02-2015, 02:39 AM
fiveforty,
I own '69Z L526897 and the engine and trans has the same 686 numbers stamped in the vin sequence. I've never seen another example. Do you have both engine and trans stamp pictures? I would like to document this irregular stamp at the LA plant since my car is one of the examples.
Mark
JohnZ
12-08-2015, 06:22 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TimG</div><div class="ubbcode-body">On '67 Corvettes they didn't use the same holder. </div></div>
That's correct - <span style="font-weight: bold">Corvette</span> was different in the 60's, and the transmission partial VIN format changed several times.
In '63-'64, the engine and transmission used the same partial VIN format (model year followed by the last six of the VIN), so the same gang holder was used to smack both parts after the transmission was bolted to the bellhousing.
That format continued into the '65 model, but it changed early in November until the end of the model year, with an "S" (instead of a number for the model year) followed by the last six of the VIN. This required different gang holders for the engine and transmission, as the engine partial VIN format remained the same as '63-'64.
For 1966, the transmission stamp format changed <span style="font-weight: bold">AGAIN</span>, adding a "6" prior to the "S123456". That format carried over into 1967, using a "7" instead of the "6".
The <span style="font-weight: bold">engine</span> partial VIN format never changed from 1961-1967; it always had the model year as the first digit, followed by the last six of the VIN. The longer-format partial VIN (18Sxxxxxx) started in 1968.
<<GRAEMLIN_URL>>/beers.gif
Keith Seymore
12-09-2015, 12:22 PM
Thank you, John.
K
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