T56 vs. TKO500/600

[dipren443]

Looking for first hand experience in regards to these transmissions. I plan on building an LSx based motor for my 73 Z/28 and was wondering if I would be best to stick with the T56 with it's not so spectacular gear ratios, or go with a TKO500/600. I have heard there are some strength issues with the 93 spec T56 trannies, which have a much more aggressive first gear and overdrive ratios. I am not looking for a daily driver, but would like a nice balance between cruising speed and acceleration.

[Mkelcy]

You might also consider the "After Market" T56, which has the 2.97 first gear (and nice splits from 1st to 6th) but is (I think) more robust than the '93 Camaro versions.

[morrisclassic]

I think that you would have less problems from a TKO600 than any other transmission. Search the net for the foot pound rating on the T56, I think it is in the 300 ft# range, not tuff enough. The low first gear in the TKO 500 3.27 may be too much for the cubic inches and torque you will be running. The foot pounds of torgue they can handle is a major factor over the weaker T56. Also the overdrive is more usable. a .64 or a .80. Gear drive for speedo is also available. No use in having two overdrive gears in a transmission. Call Charlie at Standard Transmissions in Texas, a good guy to deal with. They were offering a year / 12k mile warranty. They are an authorized Tremec service center. Hope this helps.

[TBART70]

viper t56 is very strong can hold at least 500 hp rear wheel. rockland standard gear builds one to over 700hp but over $3000.00. I bought a tko 600 for behind a 575 horse 454.

[Monzsta]

Shoot, stock viper boxes routinely see over 1,000 HP and torque with nitroused, blown and turbo'd Vipers flogging them in all manners of competition. Serious drag cars replace them with Powerglides or 400 turbo's for consistancy, not strength. The fastest manual trans cars are deep in the 8's with nothing more then a carefully shimmed stock box. I dump clutch on mine at 7 grand with slicks, and pull 3 gears without lifting the throttle.

Do a search, the T-56 internals are plenty strong. with the Camaro input and output shafts being the weak link. I've never heard of anyone breaking a Viper T-56, at least without running it out of oil first.

Scott

[morrisclassic]

I thought the guy was asking about a 93 Camaro T56 not a Viper Trans.
Of course a Viper Trans is super strong. A Viper trans is a lot more expensive than a TKO 500/600, About a grand more. I think it would
be hard to tear up a TKO 600 on a street car. But anything is possible with enough horsepower and Bite.

[TitoJones]

You wouldn't be using a 93 stlye T56 with an LSX motor anyways. The T56 will be plenty for what you are attempting, plus it was already offered from the factory. It will bolt right up.
Tyler

[79TransAm]

i plan on going with the TKO600 for my build, since it will hold 650ft/lb and i plan on having around 600. I've heard great things and never anything bad. not to mention it comes with EVERYTHING you need to do that swap, even if you have an auto originally. I'd rather spend the extra $$ now instead of being somewhere away from home when the trans craps out on me and have to spend the money then for towing and a new trans.

[dipren443]

Thanks for all the info guys. Honestly though, strength wasn't the real issue I was concerned, only that the 93 trannies are known to be weak. My biggest concern was the pathetic first gear in the T56... Minus the token two overdrives you get, the T56 has a gear spread comparable to that of a 60's M20. Case in Point:

Muncie M20
2.56 1.91 1.48 1.00

LSx compatible T56
2.66 1.78 1.30 1.00 0.74 0.50

So all you are really gaining are the two overdrives. While that is great for gas mileage, I would prefer to go with the TKO600 and get the 2.87 1st gear and 0.82 OD. I will look into the the aftermarket T56 as well. Who offers that for sale??

[morrisclassic]

Standard Transmissions in Texas, 800-783-8726. TKO 600 cost is somewhere about 2k.
Talk with Charlie. They were offering a 1 year or 12k mile warranty. Good guy to deal with.

[USAZR1]

Thanks for all the info guys. Honestly though, strength wasn't the real issue I was concerned, only that the 93 trannies are known to be weak. My biggest concern was the pathetic first gear in the T56... Minus the token two overdrives you get, the T56 has a gear spread comparable to that of a 60's M20. Case in Point:
Muncie M20
2.56 1.91 1.48 1.00
LSx compatible T56
2.66 1.78 1.30 1.00 0.74 0.50
So all you are really gaining are the two overdrives. While that is great for gas mileage, I would prefer to go with the TKO600 and get the 2.87 1st gear and 0.82 OD. I will look into the the aftermarket T56 as well. Who offers that for sale??

I've talked to a few people that are disappointed with their .82 od TKO's. They recommended the taller 5th gear.
I'm running a D&D Performance Viper T56 in my car with 4.11 cogs. The cost to my door was $2645. The new TKO's weren't available at that time or I would've looked very hard at them.
FWIW,the torque rating on the D&D T56 is 550ft/lbs. I'm sure that's a very conservative rating.

[Mkelcy]

Thanks for all the info guys. Honestly though, strength wasn't the real issue I was concerned, only that the 93 trannies are known to be weak. My biggest concern was the pathetic first gear in the T56... Minus the token two overdrives you get, the T56 has a gear spread comparable to that of a 60's M20. Case in Point:

Muncie M20
2.56 1.91 1.48 1.00

LSx compatible T56
2.66 1.78 1.30 1.00 0.74 0.50

So all you are really gaining are the two overdrives. While that is great for gas mileage, I would prefer to go with the TKO600 and get the 2.87 1st gear and 0.82 OD. I will look into the the aftermarket T56 as well. Who offers that for sale??

You can't just go by the first gear ratio. The issue is overall gearing with the rear factored in. A TKO 600 with a 3.73 rear gives you an overall spread from 10.7 in first gear to 2.39 in fifth. An aftermarket T56 with a 3.73 rear gives you an overall spread from 11.0 in first gear to 2.31 in sixth. (A slightly shorter first gear and a slightly longer top gear, with closer ratios in between because of the extra gear.) A 2.66 first gear T56 with a 4.11 rear gives you an overall spread from 10.9 in first gear to 2.05 in sixth. (A slightly shorter first gear and a MUCH longer top gear, again with closer ratios in between because of the extra gear.)

In short, if you don’t need to hold huge torque, a T56 is the way to go for the best combination of acceleration and mileage.

Sallee Chevrolet lists the after market T56 for $2295. For my money, I'd simply pickup a used LS1 T56 and never look back.

[TBART70]

rockland standard gear 1830.00 out the door without shipping and the yoke.

[parsonsj]

I sold my Viper T56 and bought a new TKO-600 (.82 od version). One of the most compelling reasons for me was the unusability of 6th in either track use or on the street.

At .5 it is just unuseable on the track: I won't be going 200 mph. For street use, the .5 means cruising speeds at 1800-2000 rpm (with 3.73 gears and 80 mph). My engine won't be happy cruising at those rpm. So bump the rear gear, you say? Sure, I could have done that but now I'm through first gear in 30 feet. That's not very useful either.

The TKO gives me less weight, more shifter options, more clutch options, more speedo options, better gear ratios, and handles more torque. So I made the switch. I'm running (using the term loosely, ha!) a 3.25 rear gear. That gives me a cruising speed of 2300-2500 rpm, long first, 2nd, and 3rd gears for track and autoX, and helps tame the 427 down by reducing torque multiplication in the lower gears.

jp

[USAZR1]

I can understand why you made the switch for your car,John,but my Viper T56's 2.66 first gear/4.11 rear combo isn't super low at all. Also,I don't agree that the TKO has more shifter,speedo,or especially clutch options than my set-up does. You really think a hydraulic clutch set-up has more options than a mechanical push-pull set-up like my D&D T56 has? I don't think so. Even if it did,there are so many options to choose from on either transmission,it would be a moot point.
Let's face it,,the TKO was a better trans for your particular combination but that doesn't mean it is for mine.

[parsonsj]

Clint,

Peace. I wasn't addressing your setup at all. I was responding to the fellow from Pittsburgh who asked the question to begin with. T56s (and especially the Viper version) are awesome transmissions; light years better from the choices I remember from my youth: Muncy, T10, and Saginaw 4 speeds.

A final comment: we can leave aside the speedo and shifter stuff, but let me say something about why I think there are more clutch options for the TKO. Any BBC (168? tooth flywheel) bellhousing made over the past 40 years will allow the TKO to bolt to an LSx engine, plus any aftermarket replacement of that bell. That's a lot of choices. And that means either a mechanical or a hydraulic clutch is possible. So yeah, the TKO has more options for clutch setups because it can be either mechanical or hydraulic, and allows use of standard BBC bellhousings.

jp

[dipren443]

I sold my Viper T56 and bought a new TKO-600 (.82 od version). One of the most compelling reasons for me was the unusability of 6th in either track use or on the street.

At .5 it is just unuseable on the track: I won't be going 200 mph. For street use, the .5 means cruising speeds at 1800-2000 rpm (with 3.73 gears and 80 mph). My engine won't be happy cruising at those rpm. So bump the rear gear, you say? Sure, I could have done that but now I'm through first gear in 30 feet. That's not very useful either.

The TKO gives me less weight, more shifter options, more clutch options, more speedo options, better gear ratios, and handles more torque. So I made the switch. I'm running (using the term loosely, ha!) a 3.25 rear gear. That gives me a cruising speed of 2300-2500 rpm, long first, 2nd, and 3rd gears for track and autoX, and helps tame the 427 down by reducing torque multiplication in the lower gears.

jp

John,

Thanks for all of the specifics. That's the kind of info I was looking for. And to respond to Mkelcy's remark. I am well aware you can't just go by the first gear ratio, that you have to look at the overall multiplication through the gears. Still, 6th is pretty unusable on the T56, especially for track and autocross purposes. I have no intentions on drag racing very much once the car is done and if the suspension I have planned works as well as I hope, then it will see alot of open track days, maybe even a One Lap of America run at some point.

[Monzsta]

John,

Thanks for all of the specifics. That's the kind of info I was looking for. And to respond to Mkelcy's remark. I am well aware you can't just go by the first gear ratio, that you have to look at the overall multiplication through the gears. Still, 6th is pretty unusable on the T56, especially for track and autocross purposes. I have no intentions on drag racing very much once the car is done and if the suspension I have planned works as well as I hope, then it will see alot of open track days, maybe even a One Lap of America run at some point.

Oh, I don't know about 6th being useable... I was ready to grab it at 160ish after I hit the rev limiter in 5th, untill common sense kicked in as I was not running on rated tires. That Z06 Vette was sure shocked as I was putting bus lengths on him all over his speedo!

6th at 70-80 cruise speeds with my 26" tire and 3.89 gear come just under 2,000 rpm, very welcome on long drives, but a touch low for the cam I'm running. (sbc, 580" 312 duration)

I'm simply going to install 4.11 or 4.56 and back off on the cam a little for a good solid do-everything combo.

Scott

[USAZR1]

Clint,
A final comment: we can leave aside the speedo and shifter stuff, but let me say something about why I think there are more clutch options for the TKO. Any BBC (168? tooth flywheel) bellhousing made over the past 40 years will allow the TKO to bolt to an LSx engine, plus any aftermarket replacement of that bell. That's a lot of choices. And that means either a mechanical or a hydraulic clutch is possible. So yeah, the TKO has more options for clutch setups because it can be either mechanical or hydraulic, and allows use of standard BBC bellhousings.
jp

No offense taken,John. We're all friends here. Just a lively discussion.
In reference to the above,couldn't my D&D T56 also use all of the same stuff? It would seem both the TKO and D&D don't care what they're bolted to or what clutch actuation they use.

I've said it before but will say it again,,if the TKO's had been available when I purchased my D&D,I would've purchased the TKO. Nothing wrong necessarily with the 6spd but the 5spd probably would be better for my future combination. Right now,the 6spd is probably a better choice for my present one.

[Damn True]

Thanks for the great info guys. I was flipping coins on the selection of a tranny and am pretty much sold on the TKO-600 now. Anyone have the ability to do a quick and dirty calculation on RPMs for me? I will be running a 315-35-17 rear tire and I'd like about a 3.55 rear gear.

[69HuggrrrPT]

This is a cool calculator/graph. You will have to put the TKO #'s and your gearing in manually though. Everyone should check it out.
By the way when and where are you getting your TKO? I'm also in the market for one.

http://www.geocities.com/z_design_studio/transmission_z28_6.html

[parsonsj]

No offense taken,John. We're all friends here. Just a lively discussion.
In reference to the above,couldn't my D&D T56 also use all of the same stuff? It would seem both the TKO and D&D don't care what they're bolted to or what clutch actuation they use.

Cool, and thanks.

The Viper T56s I've seen won't bolt to a standard bellhousing. You either have to use GM's F-body or McLeod's modular setup.

Because i'm interested, is the aftermarket version different? Does it have a standard tranny-bell bolt pattern? Does it have the standard size input shaft boss so that sbc/bbc throwout bearings work? If so, then I agree that both provide maximum possible clutch options. My comments are based on the factory offerings for Vipers and f-bodies.

jp

[USAZR1]

The D&D T56 will bolt up to a standard bellhousing. My car had a Saginaw 4spd (ughh) in it when I bought it. When we installed the D&D,we re-used the stock bellhousing,throwout bearing,and pressure plate. The clutch disc had to be changed to a 26 spline that is also used in later Muncies and Super T-10's.
Here's an article from CHP magazine that details the swap of a D&D Performance T56 trans into a 65 Chevelle.
http://www.chevyhiperformance.com/techarticles/148_0305_t56/

[Elusive R]

You can bolt up a LS1 T56 to a standard bellhousing as well with an adapter from Mcleod. How do I know? Because it's in my car. I haven't had mine up over 30 mph yet, so I really can't comment on 6th gear usefullness, but our freeways in Phoenix are nearly all 65 mph, so I'll be able to use it quite a bit.

Ryan

[protour_chevelle]

My buddies running a TKO-500 in his 89 67mm turbo'd stang... 500rwhp, he says the tranny shifts like ****. Notchy as hell for a higher end tranny. Shifting fast is out of the question. He's even let other guys drive his car and the same comments were given. A built t-56 is the way to go if you want to row gears :)

-Matt

[parsonsj]

Matt,

While it's possible the tranny is the culprit for the poor shifting of your buddy's Mustang, it is more likely a misaligned input shaft or worn clutch. Did he indicate the alignment of the bell to the block? Has he inspected the clutch for warpage or burning? That's where I'd start.

jp

[JodysTransmissions]

Matt,

While it's possible the tranny is the culprit for the poor shifting of your buddy's Mustang, it is more likely a misaligned input shaft or worn clutch. Did he indicate the alignment of the bell to the block? Has he inspected the clutch for warpage or burning? That's where I'd start.

jp
I would have to agree on this statement too. What was done to your buddies set-up prior to the TKO installation?

Regards, Jody