Motor vin stamp vs. transmission vin stamp

[BULLITT65]

Well I am not sure if this has been discussed before or not. When ( at what time during assembly, not actual date) was the motor stamped with the vin number by the oil filter, and was the transmission also stamped during this time with the vin number? Were the two mated together already and stamped with the same gang stamp? Just curious how and when this happened to both.

thanks

[1968RSZ28]

From JohnZ's Camaro Assembly Process Report...

"In the engine schedule area, the operator grabbed the next Broadcast Copy from the printer, verified the sequence number, noted the engine code required for that car, and moved an air-powered overhead hoist on traveling bridge rails over the correct engine rack. The specified engine was hoisted out of the rack and transferred to the next hook on the overhead engine dress line conveyor, where the throwout bearing (on manuals) was greased and installed, along with the clutch fork boot. Another operator on the other side of the line repeated the process with the specified transmission, which was then installed and bolted to the engine; on automatics, an air tool was used to rotate the flexplate, and the converter bolts were driven, followed by the lower cover. The VIN derivative numbers were stamped in the next operation on both the engine pad and the transmission, using a gang-stamp holder and a hammer. From here on, all the detail dress items were added (plug wires, coil, engine harness, battery cables, carburetor, pulleys, alternator, starter, fan and clutch, A/C compressor, power steering pump, transmission cooler lines and fill tube, A.I.R. pump, diverter valve and air manifolds, drive belts, dipstick and tube, oil filter, engine and transmission mounts, PCV plumbing, vacuum fittings, fuel pump and fuel line, radiator hoses, and (if applicable) the transmission-mounted 4-speed manual shifter and linkage was installed and adjusted (3-speed manual floor shifters were mounted on the cross-member and adjusted later on the Chassis line). Engine oil and transmission lube were added, and the completed engine/transmission assembly was conveyed to the Chassis Line for installation in the subframe. The engine line inspector wrote the engine, transmission, and carburetor codes on the Broadcast Copy and put the sheet in a box for pickup by a Scheduling clerk (needed to create the P-O-P at the end of the Final Line)."

Paul

[BULLITT65]

Ok 2 questions. First in Johns report, shouldn't it say Pilot bearing, instead of throwout bearing? (I thought the pilot bearing was the one fitted to the back of the block) throw out bearing I thought was mounted to the clutch fork right?

Second in your post I didn't see if they were stamped using the same stamp, or 2 different gang stamps. Looking closely at my trans and motor it appears to be a different stamp, but maybe it just looks different because it is deeper into the softer aluminum on my trans?

[69Z28-RS]

Ok 2 questions. First in Johns report, shouldn't it say Pilot bearing, instead of throwout bearing? (I thought the pilot bearing was the one fitted to the back of the block) throw out bearing I thought was mounted to the clutch fork right?

Second in your post I didn't see if they were stamped using the same stamp, or 2 different gang stamps. Looking closely at my trans and motor it appears to be a different stamp, but maybe it just looks different because it is deeper into the softer aluminum on my trans?

there's nothing wrong with how JohnZ stated it...  both the pilot bushing and throwout bearing would have to be installed prior to mounting the trans to the engine.  I've also heard it said many times in this forum that the two stampings were done with the same gang stamp (why take the time to change two different gang holders when one can do that job in a few seconds?)..  and Yes, your transmission stamping should be very clear, whereas the engine stamping (VIN) on the cast surface is not very deep, and will look differently on that rough hard surface than does the same stamping on softer smooth aluminum.

[jack92584]

My understanding is that the trans and block vin stamps should be identical as they were done at the same time. Having said that I also remember reading that there are confirmed cases very late in the 69 model year where for unknown reasons different stamps appear to have been used.

[KurtS]

I've seen a few examples in 69 where they didn't match.

[ko-lek-tor]

I've seen a few examples in 69 where they didn't match.

I guess I try to understand why there is a mismatch in some stampings when that is noted. John certainly could verify this, but a plausible reason, IMO, is that in a hurried environment and some carelessness factored in, some trans or other units may have gotten damaged before they made it into the chassis and had to be replaced, hence a different stamping. Just throwing that out there while it was on my mind.

[BULLITT65]

Bentley, I think Kurt is referring to the stamping font on the  gang stamp not matching, not that the vin numbers are different.

[ko-lek-tor]

Bentley, I think Kurt is referring to the stamping font on the  gang stamp not matching, not that the vin numbers are different.

That (font and any other irregularity in partial VIN stamp comparisons of matched block vs trans) is also what I refer, apologies for any ambiguity. If another unit (I.E. trans. or other major component) was exchanged during the assembly process because of damage on the line, the new unit would have had to have the partial VIN added on the line. That replacement's stamping may not be identical in appearance to the engine block's stamping .

Disclaimer: I am no JohnZ and was not involved in any automotive factory. This is just a supposition and opinion of what may have occured to explain irregularities in appearance of partial matching component VIN stampings. Shoot, I have not been through the Norwood plant since I toured it as a Cub Scout in 1970! I was 9 years old! Y' all have a Happy, safe, productive, New Year...like a fine wine, all our cars will literally become a year older tomorrow.

[69Z28-RS]

46!!   Prime of their lives... 

[68 Ragtop]

Ok 2 questions. First in Johns report, shouldn't it say Pilot bearing, instead of throwout bearing? (I thought the pilot bearing was the one fitted to the back of the block) throw out bearing I thought was mounted to the clutch fork right?

Second in your post I didn't see if they were stamped using the same stamp, or 2 different gang stamps. Looking closely at my trans and motor it appears to be a different stamp, but maybe it just looks different because it is deeper into the softer aluminum on my trans?

there's nothing wrong with how JohnZ stated it...  both the pilot bushing and throwout bearing would have to be installed prior to mounting the trans to the engine. 

Since the motors are already coded for transmission type, wouldn't the pilot bearing already be installed?
Perhaps that's why JohnZ didn't mention it.

[BULLITT65]

Good point.

[bcmiller]

Pilot bearing would have normally been installed before the engine and transmission were mated together.

If the partial VIN stamp on the engine and transmission do not match, that should raise a yellow flag.  It is possible they are both factory stamps, but it does raise questions and I would have Kurt take a look at both to verify.  But that is your call.

[JohnZ]

The pilot bearing was installed at the engine plant, before they installed the flywheel, clutch, and bellhousing.

There are several potential explanations for differing formats between the two VIN derivatives, most likely related to individual operator work assignments and how they changed during the year as manpower adjustments were made or as Engineering specs for each stamp were revised. Unfortunately, we don't have those records. I've always been baffled by the VIN moving in 1969 from the pad to the oil filter - the plant controlled when the alternator was installed, so they must have had another reason why they took it off the pad to the oil filter area - we don't have those records either.

[69Z28-RS]

You're not the only one to ponder the WHY of that move JohnZ...      One potential reason for that, as I ponder the possibilities, is as follows:

Supposedly the reason for the VIN stamping on the engine is for 'legal purposes'.. ie. association of the engine with a specific vehicle, theft deterrent, etc.  By 1969, many machine shops and owners were decking their blocks for increased compression, which in addition to 'removing the 'engine application stamping', would also remove the VIN (if it stamped on the deck surface.  As muscle car owners, street racers, etc..  Why should we care if those 'meaningless' stampings were removed~??       

There is essentially zero chance that the VIN would be machined away (accidentally) if it placed down there on the cast surface.   In fact, I think it was several years before people realized that Chevrolet had moved the VIN stamping to the block rough cast surface.  I believe it was around 1979 before one of the car magazines published as part of a 'Camaro Decoded' sets of articles, that the VIN stamping on the engine was moved down to the side of the block.

The 'con side' of that logic is, as we all know, it's very difficult to legibly discern the VIN on that rough cast surface even when the engine is removed and cleaned/examined, etc, and practically impossible to read the VIN with the engine in the car!