T10 question

[Terry K.]

I have what I believe is a T10 out of a 62 Corvette. Both the main case and the tail shaft are aluminum. It is mounted in my 60 and I am not able to get it up high enough on the garage floor to view the top side for assembly date stampings. My guess is that you guys have talked about T10 markings many times. I tried using the search feature on this site. However I was not able to narrow it enough to find anything. The judging manual is really not too specific, nor is my Nolan Adams Complete Restoration book.
So here is my question: The tail shaft housing has the raised bowtie with the part number and the words “Patent Pend. General Motors Corp”. Just below that is a cast in place insert with “R - 2”. What does that stand for?

[Mike E.]

Re: T10 question

Terry--
Assembly stampings are not on the top. They're on the side, on a boss, right in front of the side cover. That'll quickly tell you what you need to know. The tailshaft housing info you gave is inconsequential--they all have that info on them.

[Terry K.]

Re: T10 question

Mike:
Thanks! I'll check a little closer! It is pretty oily and a mess under there - 35 years of neglect!
I am still curious about the "R - 2" though??? It is obviouly not a normal date code. Since it appears to be an insert, they must have been documenting something.

[John H.]

Re: T10 question

Terry -

The assembly date code is stamped on a machined surface on the driver's side, just rearward of the rear upper corner of the side cover. The "R 2" is probably a mold number.

[Joe L.]

Re: T10 question

Terry-----

Keep in mind, too, that just because it has an aluminum main case and aluminum extension housing does not necessarily mean that it came out of a 1962 Corvette. The aluminum main case was used for 1961-62 Corvettes as well as 1962 Chevrolet passenger cars with 409. So, it could have been originally fitted to any of these applications. The VIN derivative stamping will confirm which. However, it's really only an academic point. Regardless of where it originally resided, the transmission would be the same.

[Joe L.]

Addendum

I should also have mentioned that while the Corvette and passenger car transmissions for the years and applications mentioned would be the same, the transmission could be either a close or wide ratio.

[Verne Frantz]

Re: Addendum

Terry has not given us enough to go on. Let's start with the assembly date stamping on the main case, just behind the side cover. We don't even know if it's a T10-1C case. Both the T10-1C main case and the T10-D1 main cases used the T10-7D extension housings. ALL '62 Passenger cars with 4-spd had the T10-1C aluminum case transmission - 250hp, 300hp, 380hp & 409hp. If a '62 dated iron case T10 is located, it is probably from a Buick, Olds, Pontiac or Studebaker, or it's a service replacement for an earlier Chevy application.

The only '61 Passenger cars with the T10-1C case were cars produced with one of the 142 409s, beginning in January '61, which I believe was before the Corvette changed from the 1B case to the 1C case. VERY late in the '62 model year, a few T10D-1 cases appeared in Passenger cars and continued until mid Feb. of '63 before the change to the Muncie.

The '61 409 T10 was a 2.20 1st ratio. For '62, the T10s were 2.54 ratio for both small blocks and 2.20 ratio for both versions of the 409 (with the 2.54 wide box available with the 3.08 rear).

But, as Joe said, each transmission "type" was identical between Corvette and Passenger except for ratio, depending on engine and rear axle options. (Except '63 409 T10s used a large diameter cast iron front bearing retainer rather than the small aluminum one for the 421 bellhousing.)

Verne

[Joe L.]

Re: Addendum

Verne-----

I believe that the T-10D main case was the 63-only case set up for the smaller diameter bearing retainer. That would not work on any C1 bellhousing. So, presuming that the 1960 in question still has a C1 style bellhousing, I don't think that a T-10 with a T-10D case could be installed.

[Verne Frantz]

Re: Addendum

I agree Joe. Assumming he still has the correct bellhousing, it would have to be the T10-1C case (unless he has a '63 409 transmission with the large front retainer)

Verne

[Terry K.]

Re: T10 question

Sorry for confusing you all so much! As pointed out, the info I gave out was sketchy at best, which set off the multitude of possibilities that you all have presented! You guys have sooo much knowledge that it is scary! I am impressed!!

Here is all the info on the T10:

The assembly stamp is WL2123 and there does not appear to be any VIN derivative date stamping.

The main case has “T10D-1” in raised letters, preceded with two insert castings: a “K” and “16”. There appears to be a third insert above the “K”, but it is unreadable – if in fact there is anything really on it!

The tail housing has:
- the raised bow tie
followed by “Patent Pend. General”
“ Motors Corp. 3816490”
“T10 7D”
“R – 2”

There is a rusted tag on the top of the transmission, but I could not get near enough to read it – it is hell to be old, blind, with bifocals! I assume this tag has the ratio info. Given how similar first and second are, I would say it is the close ratio 4 speed but don’t really know that.

So if I understand the info you have given, I got a passenger car T10, assembled Nov 21, 1962 on the third shift. It appears to be “unmolested” as the main case date precedes the assembly date by a month. (still not sure about the tail housing)

Just to clarify, the T10 is mounted to a 62’ 327 block (FI2I3RD 2104469).

Both the engine and the transmission have been mounted in my 60 corvette for the last 36 years! I was told when I bought the car (back in 1970) that the engine and transmission were out of wrecked 62. However, they do not appear to have been manufactured together.

Have I got all that right? Thanks again for all your help and your willingness to share!

[Verne Frantz]

Re: T10 question

Hi Terry,
I believe you've decoded everything correctly. It is a "'63" transmission. I'm sure the Corvette assembly line was much more judicious about stamping the VIN derivitive on the transmissions than a lot of the Passemger car plants, so if no VIN derivitive can be found, it is probably from a passenger car, or possibly it was a service replacement transmission.

You didn't mention which bellhousing is in your car. But if you've enjoyed the car for 36 years with that transmission without a problem, I'd have to guess that the trans has the correct size bearing retainer for the bellhousing. I'm not sure if you can get close enough to remove the clutch fork boot and peer in there.....

Verne