Strength of a BW Super T-10 [Archive] - Chevelle Tech

: Strength of a BW Super T-10


64CDNSS
Sep 14th, 06, 1:18 AM
I have a 2.64 first gear ST-10 in my Malibu.
They trans is basically brand new - 6000 original miles.
How much torque can these things handle?
I will be drag racing about once a month - NO SLICKS.

justkyle
Sep 14th, 06, 1:49 AM
They are pretty tough. As long as you don't really slam the gears. I blew the second gear slider out of my buddies '66/396 last year. It broke the collar off the slider. Im glad he has a sense of humor and I did it in front of his house.

Wally
Sep 14th, 06, 6:33 AM
I have a 2.64 first gear ST-10 in my Malibu.
They trans is basically brand new - 6000 original miles.
How much torque can these things handle?
I will be drag racing about once a month - NO SLICKS.

The Richmond web site has the torque ratings and they are fairly low.

Part No. Description 1st 2nd 3rd 4th Rev. Torque
1304000070 2.43 “S” Ratio 2.43 1.61 1.23 1.00 2.35 375 Ft. Lbs.
1304000069 2.64 “W” Ratio 2.64 1.75 1.34 1.00 2.55 325 Ft. Lbs.
7021090 2.64 “X” Ratio 2.64 1.60 1.23 1.00 2.55 325 Ft. Lbs.
1304000072 2.88 “CC” Ratio 2.88 1.91 1.33 1.00 2.78 300 Ft. Lbs.
1304000062 2.88 “Y” Ratio 2.88 1.74 1.33 1.00 2.78 300 Ft. Lbs.
1304000071 3.42 “Z” Ratio 3.42 2.28 1.46 1.00 3.51 286 Ft. Lbs.
General Specifications

dreis454
Sep 14th, 06, 7:18 AM
The Richmond web site has the torque ratings and they are fairly low.

Part No. Description 1st 2nd 3rd 4th Rev. Torque
1304000070 2.43 “S” Ratio 2.43 1.61 1.23 1.00 2.35 375 Ft. Lbs.
1304000069 2.64 “W” Ratio 2.64 1.75 1.34 1.00 2.55 325 Ft. Lbs.
7021090 2.64 “X” Ratio 2.64 1.60 1.23 1.00 2.55 325 Ft. Lbs.
1304000072 2.88 “CC” Ratio 2.88 1.91 1.33 1.00 2.78 300 Ft. Lbs.
1304000062 2.88 “Y” Ratio 2.88 1.74 1.33 1.00 2.78 300 Ft. Lbs.
1304000071 3.42 “Z” Ratio 3.42 2.28 1.46 1.00 3.51 286 Ft. Lbs.

General Specifications

Wally, I thought that the st10 was supposed to be equal to or stronger than an M22? Are the muncies rated for less?

Keith Tedford
Sep 14th, 06, 9:38 AM
For what it's worth, we have a 2.64-1 aluminum Super T-10 behind the 360 hp 455 in our Lemans Sport. This engine is factory rated at 500 ft/lb of torque. Probably a little high. This car is considerably quicker than our L78 Chevelle, making some decent power. The transmission has stood up to 10K miles of street tire abuse. Slicks will find the weak spots pretty quickly, if they are there. The steel mid plate and cast iron case add strength as well but not all T-10s have them. I've heard about GM going to the iron case due to warranty problems. The aluminum transmission would have to be pretty weak if the late '80s cars could hurt it. They weren't making much power back then. Perhaps I have been just lucky.

Wally
Sep 14th, 06, 10:54 AM
Wally, I thought that the st10 was supposed to be equal to or stronger than an M22? Are the muncies rated for less?

I'm glad Richmond post real life torque ratings. I think they are playing it safe. As for the Muncie, GM did not play the HP and torque game that other vendors seem to like.

They put Muncies in some real torque monsters, the 455 SD Pontiac, 455 Olds motors, 454 Chevelles and some nasty vette combos and thy seem to live:beers:

136679ss
Sep 14th, 06, 3:11 PM
Alright then what's a real world value of a 1304065903, unknown if it has nickel gears or the like but assuming it doesn't what's it worth? More than same as or less than a muncie?

Wally
Sep 14th, 06, 3:27 PM
Alright then what's a real world value of a 1304065903, unknown if it has nickel gears or the like but assuming it doesn't what's it worth? More than same as or less than a muncie?

Good question. That is the aluminum version and all the info on the site is the iron case stuff.

It is weaker the the 904 trans.

RatONaStick
Sep 14th, 06, 4:28 PM
Good question. That is the aluminum version and all the info on the site is the iron case stuff.

It is weaker the the 904 trans.

Maybe I'm misunderstanding what you're saying, but Richmond never made an St-10 with the Iron case/midplate. Those torque figures you posted above are all for the aluminum case/midplate trans with standard gears(non nickel). Borg Warner made very few of the 904 case trans compared to the aluminum case version, I have yet to see any torque figures posted on the iron case trans.

I'm running a 2.43 first 904 iron case/midplate ST-10 in my 66. Check out the track video in my sig, that's a 4200rpm launch off the two step on slicks. It seems to be holding up well, I know the Muncie I took out wouldn't hold up to that abuse, then again it is 30+ years old.

Although the car did spin on that run, I have put the trans though some abuse both on the track and on the street. I have yet to have any problems with it.

Based on my experiences so far, I wouldn't hesitate to use a St-10.

RatONaStick
Sep 14th, 06, 4:34 PM
They are pretty tough. As long as you don't really slam the gears. I blew the second gear slider out of my buddies '66/396 last year. It broke the collar off the slider. Im glad he has a sense of humor and I did it in front of his house.

The St-10 and Muncie share the same syncros and sliders. One hub is the same, the other hub(I forget which) is the same except for the inner part where it goes on the main shaft.

The Muncie is no stronger in this area than the St-10.

136679ss
Sep 14th, 06, 4:50 PM
Good question. That is the aluminum version and all the info on the site is the iron case stuff.

It is weaker the the 904 trans.
My understanding was the majority of the st10's were aluminum and warranty issues with performance cars such as the TA and z28 were the reason they even started using the cast iron, ironically most vettes still retained the aluminum case.

RatONaStick
Sep 14th, 06, 5:05 PM
My understanding was the majority of the st10's were aluminum and warranty issues with performance cars such as the TA and z28 were the reason they even started using the cast iron, ironically most vettes still retained the aluminum case.

I've read something similar. From what I understand the 3.42 first transmissions were having durability issues and BW started to use the iron case/midplate on these units to help strengthen them. I know that my 904 case/iron midplate were from a 3.42 first trans, strange though I was told it was out of a Vette.

The durability issues have to do with the 3.42 gearset, you'll notice that the 3.42 first trans is the weakest of the bunch. If you've ever seen a 3.42 input shaft, the gear itself is tiny. There just isn't a whole lot of material there.

136679ss
Sep 14th, 06, 6:04 PM
That's because corvettes would never have had a factory 3.42 gearset only 2.34 -2.88.
I've found a great homepage that details a lot of good information on the ST10
http://fiedlerh.home.att.net/BW.htm

Wally
Sep 14th, 06, 6:17 PM
Maybe I'm misunderstanding what you're saying, but Richmond never made an St-10 with the Iron case/midplate. Those torque figures you posted above are all for the aluminum case/midplate trans with standard gears(non nickel). Borg Warner made very few of the 904 case trans compared to the aluminum case version, I have yet to see any torque figures posted on the iron case trans.

I'm running a 2.43 first 904 iron case/midplate ST-10 in my 66. Check out the track video in my sig, that's a 4200rpm launch off the two step on slicks. It seems to be holding up well, I know the Muncie I took out wouldn't hold up to that abuse, then again it is 30+ years old.

Although the car did spin on that run, I have put the trans though some abuse both on the track and on the street. I have yet to have any problems with it.

Based on my experiences so far, I wouldn't hesitate to use a St-10.

I don't believe I said the trans was not up to the task, just that they have a pulished low torque rating for current production units.

The best ST-10 units were never put in production cars, the iron case units you could buy from speed shops. They are the ones available with high nickel gears and ratios no higher than 2.88 low gear. All the other stuff came later when GM starting using the trans and when Richmond took over production.

The corvette used a iron case ST-10, some time after the end of the Muncie run and I think in some of the Z cars, not sure of the years.

If there is a weak part of the ST-10 its on the front of the main shaft, that little spud that sits in the roller bearings in the back of the input. I've seen a number of those break in race car applications and high HP heavy street cars that hook.

Most of you missed the point I was trying to make, that torque and HP ratings don't mean jack:clonk:

RatONaStick
Sep 14th, 06, 7:29 PM
I don't believe I said the trans was not up to the task, just that they have a pulished low torque rating for current production units.

The best ST-10 units were never put in production cars, the iron case units you could buy from speed shops. They are the ones available with high nickel gears and ratios no higher than 2.88 low gear. All the other stuff came later when GM starting using the trans and when Richmond took over production.

The corvette used a iron case ST-10, some time after the end of the Muncie run and I think in some of the Z cars, not sure of the years.

If there is a weak part of the ST-10 its on the front of the main shaft, that little spud that sits in the roller bearings in the back of the input. I've seen a number of those break in race car applications and high HP heavy street cars that hook.

Most of you missed the point I was trying to make, that torque and HP ratings don't mean jack:clonk:

Wally

I know you werent saying they weren't up to the task, that first paragraph was directed to you, the rest was intended for the original poster. I probably should have made myself more clear.

It seemed that you were implying that those torque ratings were for the iron case versions, evidently I misunderstood you. Although it would be interesting to know how much the iron case adds to the strength of the transmissions. I can tell you one thing, the iron case/midplate sure adds some weight to the trans!:D

I remember you mentioning the mainshaft spud before. While I agree it may be a weak point, I tend to think that if a Super T10 will break in those situations you mentioned, so will a Muncie. Wouldn't you agree??

I know that if I were going to build a race car or a heavy high hp(we're talking mucho torque) street car, I wouldn't use either trans.

Keith Tedford
Sep 14th, 06, 7:32 PM
Posting low torque ratings sure gets them off the hook when things break. They can cry misapplication. Most cars make more than these ratings. Many factory hp ratings from the sixties were just as bogus. This thread brought out some good information just the same.

Wally
Sep 14th, 06, 7:36 PM
Wally

I know you werent saying they weren't up to the task, that first paragraph was directed to you, the rest was intended for the original poster. I probably should have made myself more clear.

It seemed that you were implying that those torque ratings were for the iron case versions, evidently I misunderstood you. Although it would be interesting to know how much the iron case adds to the strength of the transmissions. I can tell you one thing, the iron case/midplate sure adds some weight to the trans!:D

I remember you mentioning the mainshaft spud before. While I agree it may be a weak point, I tend to think that if a Super T10 will break in those situations you mentioned, so will a Muncie. Wouldn't you agree??

I know that if I were going to build a race car or a heavy high hp(we're talking mucho torque) street car, I wouldn't use either trans.

Sure a muncie will break, not in the same location.In my case 1st or 4th. I welded one third gear to the main drive, blasted several 1st gears and one fourth. All this with a Z28 in a 68 camaro.

But due to low funding many years ago I never had what you would call a real nice unit, lots of use parts that got abused.

A pure race application would need a much stronger type trans, GForce or a Jerico.

RatONaStick
Sep 14th, 06, 7:54 PM
That's because corvettes would never have had a factory 3.42 gearset only 2.34 -2.88.
I've found a great homepage that details a lot of good information on the ST10
http://fiedlerh.home.att.net/BW.htm

I've seen that site before, I wonder how accurate that info is. If you look at the top it says that the info is based on fact, rumor, internet stories and his vague recollection. The application data is incomplete and he mentions that it's a work in progress, so what is fact and what is rumor etc? Which is why I hesitate to treat that info as gospel.

RatONaStick
Sep 14th, 06, 8:13 PM
But due to low funding many years ago I never had what you would call a real nice unit, lots of use parts that got abused.

I'm in the low fundage situation now. There was no way I could afford a new trans or the super case/midplate and gears for my old worn out Muncie. I ran across this super t10 with a bad synchro here in town and happened to get lucky finding the iron case/midplate for cheap on Ebay. I rebuilt it myself to save money and so far it's worked out great.

I will say that although I'm extremely happy with this trans, I probably would have preferred the Muncie if I had the cash. To be honest the Muncie shifts smoother/quicker than the ST-10.

One thing I do like about the St-10 is the fact I won't feel so bad when/if it does grenade. ;)

136679ss
Sep 14th, 06, 8:38 PM
I've seen that site before, I wonder how accurate that info is. If you look at the top it says that the info is based on fact, rumor, internet stories and his vague recollection. The application data is incomplete and he mentions that it's a work in progress, so what is fact and what is rumor etc? Which is why I hesitate to treat that info as gospel.
Well unfortunately most all data not put out by the manufacturers starts out that way. Heck, look at how we treat Mortec these days though. Certainly it's not comprehensive, but it's a great start for those who haven't a clue. I would never treat it as gospel, but it was a site I located after about 30 seconds of googling and believe it is a good reference point for those persons aforementioed. Jason.

64CDNSS
Sep 14th, 06, 9:49 PM
Thanks for the input guys. Mine has a steel mid plate.
I will get back to you if I do manage to blow it up.

71454Chevelle
Sep 15th, 06, 7:02 AM
Although it would be interesting to know how much the iron case adds to the strength of the transmissions. I can tell you one thing, the iron case/midplate sure adds some weight to the trans!:D

Brandon,

I have talked to Brian at S-K Speed (the guy who built my tranny) has told me that a Super T-10 prepped like mine (2.64 / 1.75 / 1.33 /1.00 gearset, 9310 high nickel gears,modified syncros, nodular iron main case and nodular iron mid-bearing plate) would add 50-60% more strength to the transmission. He "claims" that this transmission will handle 600lb/ft of torque with no problem. I know that this depends on a lot of different variables but he has guys using them at the strip, with big blocks, N2O and slicks (off the line).

Brian told me that this tranny is the "strongest" OEM type transmission for a street/strip GM car. "In his opinion", a Super T-10 built like this is stronger than the new M-22 with the AG Supercase. To get anything stronger he says you have to go to a racing transmission like a Jerico or G-Force.

I myself am running a solid roller cammed 550HP 454 (an estimate) and have used a 150 shot of N2O with Hoosier QTP's (on the street) and have had no issue with my tranny.

64CDNSS
Sep 15th, 06, 11:09 AM
Darren, if you don't have problems with yours I will be fine with a stock unit. My 350 was dynoed at just under 400HP and I will only be running street tires.
How much did that S&K unit cost you?

71454Chevelle
Sep 15th, 06, 11:27 AM
Darren, if you don't have problems with yours I will be fine with a stock unit. My 350 was dynoed at just under 400HP and I will only be running street tires.
How much did that S&K unit cost you?

Mike,

I had my tranny built about 10 years ago, and back then it was around $950 with a core transmission that I sent him. I think Brian is abit more than that now. I think some of these Super T-10 parts are getting a little more rare to come by.

I would think you should be okay with your transmission, but then again, I'm no expert. Lot'sa torque and traction is what kills these things.

I was always under the impression that the alloy case of a standard Super T-10 is the weak link. I think with alot of power the case flexes.

I use to have a M-21 and I like the shifting of the T-10 better, much smoother.

RatONaStick
Sep 15th, 06, 2:00 PM
Brandon,

I have talked to Brian at S-K Speed (the guy who built my tranny) has told me that a Super T-10 prepped like mine (2.64 / 1.75 / 1.33 /1.00 gearset, 9310 high nickel gears,modified syncros, nodular iron main case and nodular iron mid-bearing plate) would add 50-60% more strength to the transmission. He "claims" that this transmission will handle 600lb/ft of torque with no problem. I know that this depends on a lot of different variables but he has guys using them at the strip, with big blocks, N2O and slicks (off the line).

Brian told me that this tranny is the "strongest" OEM type transmission for a street/strip GM car. "In his opinion", a Super T-10 built like this is stronger than the new M-22 with the AG Supercase. To get anything stronger he says you have to go to a racing transmission like a Jerico or G-Force.

I myself am running a solid roller cammed 550HP 454 (an estimate) and have used a 150 shot of N2O with Hoosier QTP's (on the street) and have had no issue with my tranny.

Darren

Let's see, heavy car, solid roller Big Block, Slicks, and N20 off the line?? That definitely makes me feel pretty good about this trans, thanks. :thumbsup:

I'm curious, since you mentioned that your ST-10 shifts better than your m21, what exactly was done to the synchros in your trans?? Was it pro shifted??

I know my ST10 doesn't shift quite as smooth as my old m21(that's with the same Hurst shifter). But in it's defense, it was rebuilt not that long ago with torque lock synchro assemblies. It has gotten better with use, but I wonder if it isn't the torque lock synchros that are causing it. It's not that it shifts bad, it just doesn't shift quite as effortlessly as my old Muncie. Then again, the muncie was well worn in.

Mike Feudo
Sep 16th, 06, 8:41 AM
In a heavy car you can and will break anything. My experience has been that the iron case ST-10 with anything but the 3.42 low is as good as you will get without spending a fortune. Anything with an alum. case is going to stretch the case eventually and it will break there is nothing you can do about it.

71454Chevelle
Sep 16th, 06, 10:36 AM
Darren

Let's see, heavy car, solid roller Big Block, Slicks, and N20 off the line?? That definitely makes me feel pretty good about this trans, thanks. :thumbsup:

I'm curious, since you mentioned that your ST-10 shifts better than your m21, what exactly was done to the synchros in your trans?? Was it pro shifted??

I know my ST10 doesn't shift quite as smooth as my old m21(that's with the same Hurst shifter). But in it's defense, it was rebuilt not that long ago with torque lock synchro assemblies. It has gotten better with use, but I wonder if it isn't the torque lock synchros that are causing it. It's not that it shifts bad, it just doesn't shift quite as effortlessly as my old Muncie. Then again, the muncie was well worn in.


Brandon,

Not sure what he did to the synco's I just remember him saying that he modifies them I think for smoother shifting. No it is not pro shifted.

My Super T-10 is smoother shifting and more positive feeling from what I can remember about mt Muncie (it was 10 years ago). The tranny just has Brians special syncos and I use Red Line's MTL. That stuff helps alot but I ran that in my Muncie as well.

Call Brian and talk to him if you have specific questions. He's very knowlegeable, been working on these things for I think over 40 years.

http://www.skspeed.com/aboutsk/transshop/default.asp

RatONaStick
Sep 16th, 06, 11:05 PM
Thanks for the info Darren.

I've been thinking about stepping up to the 2.64 gearset, if and when I do I may talk to Brian about his synchros. I've even thought about having the trans pro shifted, but probably won't for fear of shifting issues on the street.