Technical BW T10 ID Questions

Yes, I have done research and searched far and wide, and have some questions to satisfy some curiosities I have about the transmission I just purchased. I found it on ebay and was advertised to come from a 1962 Corvette and be close ratio. It is a T10-1C, which was used in the 61-62 corvettes according to the internet, so that checks out. It also has a T10-7D tail housing, which also checks out as being from a 62 corvette, but the date on it is 12-9-66. Also, the weirdest part, is the production stamp on the main case - WD1472. Based on my research, it was built by Warner Gear, April 14 19x7, on second shift. What puzzles me, is what year exactly, and can that be right? 1957 or 1967? If the -1C's were only used on 61-62 corvettes, how could it have been build in 1957 or 1967?

I bought a Hurst shifter kit for a 1962 corvette with the BW T10, I hope it's right! Hopefully someone can shed some light.

 

Every T-10 I’ve had were a mixture of parts also. Only the one new Muncie I bought was “pure”.

 

The color difference in the trans case and tail housing may indicate it being added later.
As with many Corvette parts, Shrouded in mystery.

 

I can understand that, which is why I am not too puzzled by the mis-matching tail housing. it will do fine for me. But the prod code on the main case really bugs my curiosity, mainly the year built, when supposedly it was used on a 62 car.

if the T10-1C case was only used on 1961-1962...why a prod date of a year ending in7???

 

I have a wide ratio T 10 out of a 1961 or 1962 vette it has 1 grove on the input shaft and a cast iron case.

 

Could have been a service replacement from GM. Generally they don't change the casting number unless the design is materially changed.

 

interesting....so still the T10-1C design, but produced at a later time?

 

Yes.

Consider what you have was a “Performance Part” in the first place. It has been around for about 60 years. Lots of use and maybe abuse in that time and being rebuilt a time or five is not unlikely. The main case was probably replaced . As long as it is currently in good condition it’s history doesn’t matter much unless you are doing a ‘date code correct’ restoration.

Ray

 

Not a uncommon occurrence. Say the original trans got exploded or stolen; 'Vettes weren't that common in wrecking yards, so a new one would be ordered from GM who if they didn't have one on a shelf would then order it from BW (the OEM supplier). It could even be a service replacement for a later Muncie if the architecture is correct. The Muncie was introduced in '63 and the early versions had teething problems, GM 'upgraded' the Muncie several times to address these issues. May even have been originally installed in production if GM had a shortfall in Muncie availability, although that was more common at Ford than GM.

The BW T10 was the only 4-speed available to Detroit from 1957 through 1962. GM had exclusive use through 1960, in '61 they started selling to all comers so they appeared in Fords in late '61. The problem was the motors had gotten larger and more powerful and the T10 was at it's design limit, leading to the development of the Muncie in '63 then the Ford and Chrysler 4-speeds in '64. Chrysler was the only Detroit manufacturer of the era who never used the T10.

One interesting tidbit is the T10 was actually designed and patented by GM, but at the time GM didn't have the money to develop it so turned it over to BW, who based their version on the T85 3-speed to save tooling costs. BW built it under license and paid GM royalties for every one sold. That's why the T10 and Muncie look so much alike. That's also why the Muncie never achieved the same reputation for strength that the Ford and Chrysler 4-speeds enjoyed.

 

I believe the 1980's Z 28 used the super t 10 as well as the Richmond Super t 10 which i believe is still bring made .I believe the counter shaft is 1 inch instead of 7/8 as in the t 10.

 

wow, thank you for the great info! i had not learned that much in all the searching I did online previously.

The trans and internals look in great condition...we will see how long it lasts behind an LS...

 

SD
The B/W Super T-10 started appearing in GM cars in the early/mid 70's, I bought a used one for my bracket car in 1975/76 and was told it had been "freshened up".

 

The T10s main flaw (besides it's power-handling capacity) was a tendency to pop out of gear on deceleration after they got a bit worn, usually in 2nd gear. Generally the only real fix was replacing the complete syncro ***embly and the offending gear, not cheap to do. BW addressed this when they upgraded to the Super T10, using a 'back cut' design that locked them together better. Supposedly there was a 'retrofit kit' to install the new-design syncros into the early trans, but as that entailed replacing every spinning part except for the main shaft, cluster gear, reverse and bearings it wasn't very popular as it was not much more for a whole new trans.

 

Back in the day I saw a lot of the Chevy design transmission cases with busted off mounting ears by people who didn't know how to install them properly.
That might be the reason for a later casting date...i.e. replaced main case

 

I have a friend that taught me the trick to correct popping out of second gear,it is not what you think. I have a gl*** 29 model a with a 427 sbc t-10 trans and a frankland qc weighs 2255.My trans teacher taught me weight and traction is what breaks driveline parts.The aluminum cases used to oblong the counter shaft hole so they used to replace the cases,now they can repair them.

 

ALL Super T 10’s were Underrated and the Nodular Iron Case Super T10 is the strongest out of all the old 1970’s + era. even the 2.43's aluminum case vs. Nodular Iron. 375 tq alum vs. over 450 tq for the Nodular Iron.nastyz28.com/threads/maximum-torque-for-a-super..

 

I've had issues with the iron case T10s popping out of gear, it's not a case problem....

 

No it is a haircomb problem

 

Every Saturday night dirt track car with an aluminum 4-speed that hit the outside wall a few times broke off the top left ear...

 

Steve
You've no doubt seen my prior posts on this subject but for those that havent...........
The T-10 popping out of gear on decel. will really get your attention the first time it happens, especially if you had never heard of it as was the case with this 16 year old kid.
It made a real "wind up" sound and as most people did back then, I had my hand still grasping the Hurst "T" handle when the shifter was pulled out of my hand when shifting down to second gear decelerating down a hill and popped into the neutral position.
I was a bit rattled to say the least.
I replaced the Fenton shifted three speed in my 57 in 1971 with a T-10 and apparently it was a well used one because shortly after it started popping out of gear.
So not knowing what else to expect I bought another one from a local trans shop that had been built for a drag racer that never picked it up, it had a Ford high nickel gear set and as you know it has a different spline count on the input shaft, easy to remedy by simply using a Ford app clutch disc but I bet the next owner had a surprise at new clutch time.

 

LOL

 

The torque handling capacity when choosing a transmission isn't something that a lot of people pay much attention to, guessing T-10's and Muncies' won't be taxed by garden variety small blocks but hot rodders being what they are may want to swap in an engine more "blessed" and find they made an expensive mistake and most times it involves more than just a trans swap.
When I was researching transmissions for my roadster I didn't find a lot of this kind of technical information but stumbled onto this chart from Richmond and found they offered a number of first gear ratios which often wont be found in OEM transmissions.
Ultimately I chose the one highlighted in yellow based on having the highest torque handling rating, though I originally had hoped of getting one with a lower first gear.
This chart is fairly dated, Richmond may have more options now.

 

A lot of great info, thank you so much everyone!

Another question...i need to replace the tail housing output seal. What vehicle should I get the seal for, since that housing is from 1966? Something with an early Super T10? The OD of the seal i need has to be about 2.37, as measured with calipers.

 

Looks like they are the same but here are plenty of resources to confirm.

https://www.google.com/search?q=bor...34AmUQ_AUoAnoECAQQAg&biw=1280&bih=800&dpr=1.5

 

But they should pay attention... Time and again, it's 'I need a trans that'll take X hp' but HP isn't the metric you want to use. A quick example would be comparing a '70 LT-1 350ci at 370 HP to a similar-vintage L35 396ci at 'only' 325 HP. The big block is down 45 HP compared to the 350, but at 410 ft-lbs of torque, it's got almost 40% more than the LT-1 at 300. Guess which one will break a trans quicker.... For the Ford guys, a Boss 302 makes 290 ft-lbs, a Boss 351 (basically the same motor, longer stroke) makes 370 or 80 lbs more.

And a good-sized chunk of that torque increase is due to the increased stroke. A 'mild' 383 stroker can easily make close to or equal torque as a big block, exceeding the transmission torque rating. Same goes for rear axles; they also have torque ratings.

 

An "original" case could very well have had some damage, such as ears broken off (common issue), wallowed out counter-shaft bores, etc. If it needed the main case replaced, and all the NOS parts were already used up, so either a new, "newer" part was subs***uted, or a good used, but again. a "newer" part was used. Some guys don't care about numbers matching, others have to have everything done just right. Old cars have old parts, that are't always available for replacement use, and you have to use whatever's available. Why not try to see if you can find a NOS/replacement/used part, just to see how much someone's asking for one to put their kid through college? I typed this up earlier today, just did't post it, so some of my answers are the same as others have been. The spare engine and transmission for my 56 Sedan Delivery is a .040 over, 340 HP, "327" short-block with 461-X heads (done up "old style", port and polish, pinned studs, and all new valves-springs-retainers), and connected to a B-W Super T-10 with the 2.64 first gear. It has a MOPAR, Pistol grip shifter that I've modified to accept a "regular" Hurst stick. Currently, there's a 327 with a Muncie 4-speed in the car, and 4.88 gears in the rear end. I am Butch/56sedandelivery.

 

yeah I did a quick search last night, and couldn't be 100% sure if they were the same or not. Will do some more looking today. Hopefully Advance Auto has one, because I have a coupon

 

so according to rock auto, there are multiple size seals for the same vehicle....

1966 corvette with 327 motor and manual trans have 27 OR 32 spline output and they are different sizes.

for a 1962 corvette, there are less options, but still different sized seals listed.

One of the common part numbers between the 2 selections is National 9613S. According to rock auto, those dimensions fit what I need so I think I will go with that one.

 

FYI, that 9613s rear seal fit perfectly in my 7D housing with 16 spline output!