Vette5311

Help:
I recently became the proud owner of a 1966 Big Block Roadster, NOM and now I find non original transmission. Now here is the thing. The front bearing retainer where the T/O bearing slides has a groove from heavy wear. (it is aluminum and that should have been my 1st tip off) I had an old S T10 that was trashed and thought I will just take the bearing retainer off of it, no big deal. Well it seems that the S T10 (iron) one is much larger in the bearing area. I started digging farther and the trans has T 10 D1 on the side above the fill plug. After some internet research it seems that this was a 1 year only trans in 1963 for 360 hp Corvette and full size 409 cars. The trans is all aluminum, no cast iron side cover or bearing retainer and as I mentioned the input bearing is much smaller in size that either the S T10 or the Muncie. Now on the Chevelle Forum there is a thread about this and it says that this is the best T 10 made, supposedly stronger than the S T 10. (oh yeah, it does not have the iron mid plate, that is aluminum also) The car is getting a new engine, BB 402, mild comp cam, 10:1 compression, intake, Holley, guessing around 400HP.
So now the questions:

Does anyone make a speedie sleeve to repair this like they do for balance dampers?

Is this trans really any good, or is it like the older weaker ones?

Would I be better off with a Muncie and sell this trans?

Because of its apparent rarity, is it worth good money to a restorer looking for a 1 year only trans for a 409 or 1963 Corvette? (I would like to put a 5 speed in if this would fund it)

Is this really as rare as it appears to be?

Thanks in advance for the help and input.

Critter1

Sounds like you have an old T10 from a 1963. That was the only year that used the small front bearing and retainer. If the OD of that retainer is the same as the hole in the bell housing, that means the housing is also from a 63.

More than likely, the hole in the bell housing is the larger size for 64 and later Muncies. If not, you should also replace the bell housing with a later one.

The front bearing retainer should fit the hole in the bell housing for proper transmission alignment.

Vette5311

I never looked at that, but it is a 621 bell-housing so I bet the hole is larger. Nice catch, thanks.

Critter1

I would think that the old T10 would be worth at least as much in trade for a proper muncie. The shifter would be different and so would the front yoke of the drive shaft. The front yoke is rare.

Vette5311

I don't have the trans out yet. Are you saying the yoke size diameter and spline count is different than the Muncie?

Critter1

If the transmission is a 63, (and it must be) then it will have a coarse spline output shaft which is basically a 63 only spline count. For 64 and later (with one exception) all 64 and later will have a fine spline output shaft.

Other than the number of internal splines, the yokes are about the same.

Vette5311

Good to know.

Vette5311

I found something that says these transmission had gears with high nickle content, maybe that is why the Chevelle guys think it is so good. Anybody know anything about that?

GUSTO14

I really know nothing about these, but in case you may find them useful...
GUSTO

GTOguy

An aluminum T-10 is in all cases weaker than a Muncie transmission. The strong T-10's are the later ST-10's with the cast iron 904 case and high nickel gears. These are 60% stronger than the old style aluminum T-10's. If I were in your shoes, I'd upgrade to a '66-up Muncie transmission.

DZAUTO

As I have understood it for MANY years, in about 1962, the 4sp gears were manufactured with a higher nickle content. BUT, I have never been able to talk to a human being that was involved in the metallurgical processes of gear production and durability. Again, as I have always understood, one of the factors that influenced the the need to produce gears which were stronger and could withstand higher stresses, was the higher horsepower and higher torque of the 409 engines. Is that really true? I don't know, but some people with direct connections to the internal engineering of GM have provided that information.
Maybe John Hinkley can add to this if he chimes in.

Vette5311

Forgot how much fun removing trans and comp + shifter from early Corvette can be. Clearly an April 1963 Unit and has the coarse spline output. Except for some wear from the T/O bearing on the front bearing retainer not in bad shape.

plaidside

My son had the same issue with his 64. He had a 63 T-10 with the aluminum bearing retainer and it was extremely worn. He also had a 64 bell with the larger hole.
I called Larry at D & L transmissions and he sent me a cast iron retainer that fit the T-10 and had the larger diameter for the bell. Give him a call.
What were the engineers thinking making that retainer out of aluminum is beyond me.
Joe

DZAUTO

DUH!

Now, just for added information.
For those folks who may have a 63 4sp (with the small front bearing retainer, alum or iron), and it is bolted to a 64-later (or 62-earlier) bell housing with the larger hole, the front bearing retainer on the old 55-62 3spd trannys is a direct fit to your 63 4sp. ALLLLLLLLLLLLLLLLLLLLLLLLLL 63 Chevys (pass car, Corvette, whatever) for some dumbazz reason got a bell housing (421) with the smaller hole and the smaller front bearing retainer on the transmission. EXCEPT, EXCEPT, EXCEPT the 63 409 cars!!!! The 63 full size 409 cars still had the open bottom alum bell housing with the bigger hole (which was last used in 62 on everything else) and the 63 4spds in 409 cars got the front bearing retainer that was the same as 55-62 3sp trannys. Bet ya didn't know that!

Vette5311

I will be looking for one of these from a 3 speed as the aluminum one really shows some wear.

Vette5311

I agree, I think I have a line on a muncie that is a close ratio which would give me about 9.0 total 1st gear, ratio which should be very nice. The only thing is the car has a 4.11 rear which may be a bit to low for comfortable cruising. I looked at a ZT S T-10 which is about the strongest one made of aluminum, but it is only rated at 345 ft/lbs and that is probably not enough for a big block. I have a competition + shifter that I sent to Hurst for a rebuild and then the only other thing I will need is a new slip yoke for the Muncie. I will go through the old T 10 and then put it up for sale to regain my money for this new unexpected venture. Hopefully there is someone out there doing a 63 restoration that will need this old one for it numbers.

GUSTO14

Did you verify that you have the '63 bell housing for this transmission (with the smaller hole for the smaller front bearing retainer). Or do you have the bell housing for the later transmissions with the larger front bearing retainer.

GUSTO

Vette5311

I have the large hole later one for the bigger bearing. Thanks

Dan Hampton

Tom, you are a fount of knowledge. Always instructive; always passionate.

Vette5311

That's what I really like about this forum. There is always someone out there that knows the answer to your problem and is more than willing to share that knowledge.
Thanks guys