3857584 tail housing date codes

[Jim C.]

Re: 3857584 tail housing date codes

Ronald,

I'm ALWAYS interested in "the numbers." For some reason, I really enjoy finding numbers and date codes on my car. Just when I think I've found them all, someone posts something I didn't know, and I'm off on my next "hunt" right in my own garage. I never knew what any of those circles and dots meant. Now I know. Good stuff. I guess it's my way of documenting the authenticity of my Corvette's components. There's a lot to learn, but I'm enjoying the process. I'll let you know what I find on the transmission case.

Jim

[Wayne M.]

Re: 3857584 tail housing date codes

.....Just when I think I've found them all, someone posts something I didn't know, and I'm off on my next "hunt" right in my own garage. I never knew what any of those circles and dots meant. Now I know. ....

Jim -- time to get your head under the OTHER side of the car .

Pics of shifter sidecovers with date and revision circles info.

Fourth pic goes with the passenger side of the maincase on the first pic. You can see the assembly date P0308, maincase cast 3rd week of Feb; sidecover seems to have many dots to correspond with the casting/assembly info on the maincase -- probably not original cover.

2nd pic is of a 3950306 sidecover, unique to 1969 '660' maincases. Note the shifter shafts (threaded, not studs).

Third pic is off a Corvette Muncie assembled P0211. Again, I see a '2' with 4 dots (too many if the dots are weeks, to agree with Feb 11th assembly. But I really think this trans is original A-Z.

Sometimes, the cast dates (number / dots) don't match up with assembly dates. Can be several reasons -- Over past 45 years, trannys may have been rebuilt with donor parts; or, original parts but the casting was careless w.r.t. date info.

Note to all: notice the revision circles with the letters CM above the bifurcation line; I always thought it was G.M., but apparently no.

Lots of fun .

[Jim C.]

Re: 3857584 tail housing date codes

Hey Wayne,

Thanks for the extra photos. I'll be checking those next for sure. I'll let you know what I find.

Jim C.

[Jim C.]

Re: 3857584 tail housing date codes

Ronald,

Here's what I found on the right side of my transmission case:

I already knew the casting number, 3885010, and the assembly date, P0719. As I stated the other day, my tail extension is part number, 3857584, and the casting date is "6" with one dot, both in a divided circle.

The casting date on the right side of my transmission case, however, is a "4" with one dot. Based on what you said earlier, it would appear that my car is the opposite of what you've seen for 1966 examples. My tail extension casting date is just a month or so (June, 1st week) ahead of the transmission assembly date (July 19), but the main casting (April, 1st week) is about four months ahead.

I'm certain the assembly date stamp (P0719) is correct and original for my car. I can clearly see that no grinding or alterations have taken place and I can document that stamp as far back as 1982 when a previous owner recorded it during a restoration. I'm going to see what I can find on the other side of the transmission case. I already know the left side of the main case has number 3884685 on it, as well as my VIN derivative, which also appears to be an original, unaltered stamp. I'll report back. Stay tuned.

Jim.

[Jim C.]

Re: 3857584 tail housing date codes

Okay Wayne and Ronald,

Back from the garage, and after some grunting and groaning to squeeze under my car, I pretty clearly saw the left side cover (with a flashlight and a magnifying glass), and casting date code is "5" with one dot, both inside the circle. I guess that means May, 1st week. It seems like I've got a "collection" of dates on the transmission.

Main casting date: 4, 1 dot (April, 1st week)
Cover casting date: 5, 1 dot (May, 1st week)
Tail extension: 6, 1 dot (June, 1st week)
Assembly date stamp: P0719 (July 19)

I guess it could happen that way. What do you think???

Jim

[Ronald L.]

Re: 3857584 tail housing date codes

Jim, I don't recall seeing this - What is your car build date?

[Ronald L.]

Re: 3857584 tail housing date codes

Wayne - in the photos of your main case...
Did you note those two little "dimples" after the date???

[Jim C.]

Re: 3857584 tail housing date codes

Hey Ronald,

My build date is K28 = July 28, 1966. The VIN is 6S127592. It's 128 cars from the end of production. Based on some rough calculations, I think my car was probably built near the end of the day on the 28th. 1966 production ended on Friday, July 29th.

It seems like you're not too sure about the dates from my transmission. That's okay. I'm used to having these sorts of "issues" with this car. Since it was built so late in the 1966 production run, it has several 1967 parts on it that I believe are completely 100% original to the car, including the cylinder case, cylinder heads, battery tray, distributor, etc. When the motor was completely overhauled in 1985, the owner actually found the remnants of a "Number 1 Team Chevrolet Flint Engine" decal on the front of the right valve cover. The factory supposedly didn't start applying those decals until 1967. The guy who owned the car back in the early 1980s also did a great job of recording "the numbers/date codes" on many, many parts and components. With the exception of the carburetor, all the parts are still on the car. He earned Top Flight in 1986. I earned it again in 2007 (w/o driving points). I'm pretty sure most of the parts/components on this car are the SAME ones it had from the factory, including the transmission. It certainly doesn't look like any of the numbers, stamps or date codes were ever altered in any way.

Now that I've gathered all the numbers/dates from my transmission, I'd be interested in your thoughts, good or bad. So, fire away. It's okay. Like I said before, I'm ALWAYS interested in learning more about my car. Thanks for all your responses so far. Good stuff.

Jim

[Ronald L.]

Re: 3857584 tail housing date codes

Jim,

Now that I know the VIN and the trans date they fit exactly the pattern I am seeing late in the 66 model year 7 - 10 days trans to car. The fact that some of the parts were cast earlier - the norm too. I have just started to look at the tail and cover dates and had not prior to now, so with fewer parts to go off of, they again seem normal in that there is more scatter. One thing I have not seen is a tail date significantly less that 8 weeks to the trans/car.

At the end of a production run, that last week or so lots of stuff can happen - still does - but given the trans was essentially the same crossing the model year, doubtful we'll see one that was stuck in a corner for 6 months showing up. Always a chance, but not the norm.

Did you find a number on the firewall? Others on the inside of trim panels? That number would be real interesting to know given the EOP date of your car.

[Wayne M.]

Re: 3857584 tail housing date codes

- in the photos of your main case...
Did you note those two little "dimples" after the date???

Ron -- yes, I'm guessing that those are the assembler's personal stamp. You begin to see this on some of the 1966's. (I can't recall if '67s as well).

Sometimes it is a half-height character in the shape of a square with the right vertical side removed, leading some eBay sellers on benzedrine to claim it's a "C" and therefore they have an M22 .

[Jim C.]

Re: 3857584 tail housing date codes

Hi Ronald,

I took a very close look at my firewall, and the inside of my door panels. I didn't see any numbers. I've looked for them in the past, but I didn't see any. I suspect if the numbers were there at one time, they're probably gone now. I know for sure that the owner who had the car in the early to mid 1980s did do some restorative work to it. One of the things he did was to overhaul the engine and transmission. I have a photo of the firewall with the motor and transmission out of the car. Unfortunately I don't see any numbers. I don't know if he "cleaned" them off or not during the restoration. Maybe I'm not looking in the right place. Can you tell me where to look? Also, I do know that the same former owner replaced the interior door panels in 1984. I know this because using a black magic maker, he initialed and dated the back side of the replacements with, "D.R. 8-23-84."

One interesting thing that I did find while looking down into the interior of my driver's side door was a 2.5" x 3.25" photo of a young girl. She's probably about 10 - 12 years old, and the photo probably dates from the late 1970s to early 1980s. The photo appears to be posed and taken in a studio or perhaps as a grade school picture. Unfortunately there's no name or writing of any kind on it. I suspect that it's been in the door since the 1980s because the former owner who replaced the interior door panels would have surely found it. Maybe I'll post it to see if anyone recognizes the little girl.

One other thing that I did find was one small dimple immediately after the assembly date (P0719) on my transmission. It follows behind the "9". At first I thought it might be some tiny casting imperfection, but with a good flashlight and a magnifying glass, it's clear that it was intentionally stamped there.

Are you doing some sort of transmission study??

Jim

[Ronald L.]

Re: 3857584 tail housing date codes

Jim,

In a sense these numbered parts have a real history or story to tell and in sense yes as a part of this study we are establishing or preserving the history of these cars.

I would really like to see the photos when you get a chance.

My car is a St Louis, so this is what the dash serial looks like:

well this site is smart, if you have posted the photo once it know it, here is the thread...

https://www.forums.ncrs.org/showthre...76495&uid=4507

[Jim C.]

Re: 3857584 tail housing date codes

Ronald,

First off, thanks for your responses. I've learned a few more things about my car, and that's ALWAYS a good thing!!! But I'm not entirely clear, are you actively conducting some sort of survey (keeping records, etc.) about transmissions? Are you trying to collect data from several cars? If so, I'm glad I could tell you a little bit about my car's transmission numbers and date codes. Also, it's been a good learning experience for me.

As for posting photos, that could be a little tough for me, being as "electronically challenged" as I am. Maybe my wife or kids could help me with that. I'm also not so sure how good any photos might be with the transmission being under the car. As you know, it's not easy to get at. What photos are you interested in?

Jim C.

[Jim C.]

Re: 3857584 tail housing date codes

Ronald,

I did manage to take a couple photos of the right side of my transmission. I used my cell phone and the photos didn't come out too bad. Actually most of the photos were just okay, but two of them looked pretty good.

One clearly depicts the transmission's assembly date code (P0719). In an earlier post, I mentioned that there was one dimple immediately following the "9". Well, upon reviewing the photos, I can see that there's actually two dimples, just like in the photo Wayne posted above.

The second photo depicts the transmission case date code. If you look closely, you'll see a "4" with one dot just below it. To the far left is the assembly date code.

If you send me a PM with your email address, I'll try to send these two photos to you. I tried to take a few photos of the extension, but they didn't come out clear enough to be of any value.

Jim C.

[Ronald L.]

Re: 3857584 tail housing date codes

Jim,
Yes, on the study, assembling the data as questions come up/ time permits, of course the photos help a lot. I'll look at those now. thanks.