tremec T-56 vs T600

[charlandk]

Looking at a my first cobra.
Roush 427 sr/tw
LSD final drive gear 3.46
Which tranny would you prefer and why?
Tremec T-56 or the T600

Thanks,

Kevin

[scotthei05]

T56 - get the 2.29 first gear

[Rwillia4]

T-56 if you have room for it ...it is longer than most transmissions. There is always a gear to fit what you are doing. It can do short track and still has a top gear for highway driving.

[joyridin']

I would find out what the torque curve on the engine/cam and then make a decision. With a T-56 with .62 overdrive and roughly 27" tall tires, you will be running at 1941 RPM at 70 mph. If you have a decent cam and the car isn't fuel injected, it may not be that great of a scenario.

[blykins]

No reason for a T-56.

A regular T-56 will not have the necessary torque capacity and a Magnum T-56 is $$$$$.

As mentioned, the T-56 is a lot larger and heavier.

When a TKO 600 will hold 600lb-ft and is very cheap compared to a Magnum T-56, there's no reason to spend the extra bucks. It's basically just bragging rights to say that you have a 6-speed.

[Cashburn]

No offense but I've got to disagree here based on driving cars setup this exact way. The standard T56 in a lightweight Cobra is up to the task, based on what I have seen thm hold in a late model Terminator that is significantly heavier and over powered.

As for the gearing the 2 ODs are a dream come true when you are stretching it out or freeway cruising for extended times. The t56 goes in the later BDRs fine with a SBF or FE. I like them a lot, now that I have gotten over my fear of shifting to 6th!

[blykins]

No offense taken, everyone has their own opinions. It seems to be the trend here lately....aluminum vs steel flywheels, roller vs flat tappet, TKO vs T-56...

[RICK LAKE]

charlandk Kevin If you are going to abuse this car a little, I think the Richmond super street is the answer. Same width as a top loader. Trans mount needs to be moved 1" back to fit. Couple of 1 gears to choise from and 2 different overdrive gears too. You can also get a custom Mustang handle to look like the orginial setup. Unless you blue print the other 2, neither would be my first choise. Remember you get what you pay for. Richmond is about $800.00 more but is better engineered trans to start. Rick L.

[undy]

Originally Posted by RICK LAKE

charlandk Kevin If you are going to abuse this car a little, I think the Richmond super street is the answer. Same width as a top loader. Trans mount needs to be moved 1" back to fit. Couple of 1 gears to choise from and 2 different overdrive gears too. You can also get a custom Mustang handle to look like the orginial setup. Unless you blue print the other 2, neither would be my first choise. Remember you get what you pay for. Richmond is about $800.00 more but is better engineered trans to start. Rick L.

dunno... I had a Richmond 6 speed (same 1-5 gearsets as the 5 speed) in a 496 power 69 stingray I owned. I completely stripped all the teeth off second gear & idler on a hard 1 to 2 shift. The POS weak Dana 36 even held up where the Richmond failed. Richmond's "Super Street" 5 speed is also rated at 600 lb ft.

[RICK LAKE]

Undy who sold you that bill of GOODS?? I have a 6 spd richmond When they first came out, in 1 or 2 info packet it said that this trans has a MAX RATING of 450 ft pounds of torque and 450 HP. This was max. If you push the trans beyond this limit, shifting could be a problem. My 452 made 448ft of torque. Richmond said I was right at the limit. This also was to be normal driving, NO SLICKS or AUTO CROSS tires with under a 200 thread rating. The only savings grace was the weight of the car and not hole shotting it. I was also looking for a trans with overdrive and 1/4 mile gearing. Problem is 3.25 first gear is too tall and never used unless pulling trees out of the ground. With 3.31 gears, there is too much of a drop between 1-2 shift. I asked G-Force if they blueprinted this 6 spd, answer was no because they where going to make there own 5 spd that would take 750/750 torque/ HP. I ended up buying a G-Force due to the trans shifting problem with the centerforce clutch issue. I am going to buy a super street 5 speed for the 498 motor. Will also be dropping the rearend ratio to 3.07 with 30 spline axles and carrier. Rick L.

[charlandk]

thanks everyone for your replies and advice.

[undy]

Originally Posted by RICK LAKE

Undy who sold you that bill of GOODS?? I have a 6 spd richmond When they first came out, in 1 or 2 info packet it said that this trans has a MAX RATING of 450 ft pounds of torque and 450 HP. This was max. If you push the trans beyond this limit, shifting could be a problem. My 452 made 448ft of torque. Richmond said I was right at the limit. This also was to be normal driving, NO SLICKS or AUTO CROSS tires with under a 200 thread rating. The only savings grace was the weight of the car and not hole shotting it. I was also looking for a trans with overdrive and 1/4 mile gearing. Problem is 3.25 first gear is too tall and never used unless pulling trees out of the ground. With 3.31 gears, there is too much of a drop between 1-2 shift. I asked G-Force if they blueprinted this 6 spd, answer was no because they where going to make there own 5 spd that would take 750/750 torque/ HP. I ended up buying a G-Force due to the trans shifting problem with the centerforce clutch issue. I am going to buy a super street 5 speed for the 498 motor. Will also be dropping the rearend ratio to 3.07 with 30 spline axles and carrier. Rick L.

I think at the time 450 lb ft was all that was available out there for an across-the-counter tranny. I do remember that their Road race 5 speed was rated about the same. No super street then. I think the TKO competition finally got them to beef things up.

I do know I was pissed when it happened. I didn't even hit it with the 300hp fogger shot I had on the car too. That would have splattered the whole drivetrain.

[mikeforte]

Hi charlandk,

I want to add some important info to this discussion. Being one of twelve Tremec Elite Distributors worldwide I am more than qualified to compare the the TKO-500 & TKO-600. All models of the TKO-500 & TKO-600 are very good gearboxes and capable of high horsepower in many applications including Ford, GM, Mopar, AMC and now import models too. All of the TKO models have multiple shifter locations and both mechanical & electric speedo drives.

The original T-56 that I used to sell has now been updated by Tremec to the T-56 Magnum or OEM version of the TR-6060 that is used in the Viper, 2010+ Camaro & GT-500 Mustang & more.
The TKO-600 with it's 2.87 1st gear and the .64 5th your RPM drops 36% from 3000 RPM to 1920 RPM. With the .82 5th your RPM drops 18% from 3000 RPM to 2460 RPM.

The T-56 Magnum with it's 2.66 1st gear you have 2 overdrives to choose from. The 3000 RPM with the .80 5th gear drops to 2400 RPM. The .63 6th gear your RPM drops 37% to 1890 RPM.

So in summary the T-56 Magnum can split the ratios to being two transmissions in one. Yes, the Magnum weighs a little more , but it offers more strength and more ratios built in. The T-56 Magnum, like the TKO-600 & TKO-500 feature multiple shifter locations and both mechanical & electric speedometer drives. We also have custom bellhousing for many many engine combinations. The T-56 Magnum also has a 2.97 1st and a .74 5th and .50 6th.
Forte's also manufacters external hydraulic slave clutch fork release kits in many styles.

If you have any questions, please feel free to contact me for help in pricing and fitment.

[PANAVIA]

I love my T56. compared to TKO ( any TKO ) the T56 is a really nice piece of hardware.

It may have a lower torque rating, 440LbFt for the FR T56 M-7003-H version, but a neat enjoyable *usable* gearbox.

Add a TRIAX shifter and it is aston martin slick.

If you plan to abuse the car then I can see a TKO600, but if you plan to drive the car. -- then a T56.

With the 4,5,6th gears I have several choices in most 40+ mph traffic conditions that match the situation perfectly. with the T56 I never feel like I am in the "wrong gear" for the situation.

Low speed --"Street-to-street" is beautifully handled in 2nd and 3rd , not to tall, not "panzer--tank"low --= just awesome.

Hope this helps.


Steve

[undy]

Originally Posted by PANAVIA

If you plan to abuse the car then I can see a TKO600, but if you plan to drive the car. -- then a T56.

I do agreee. I agressively drive mine with M/T ET Drag Radials so the TKO's strength is greatly appreciated. I've already had to dump the 28 spline 9" rear axles for some drop-forged 31s and a True-Trac diff. The 28s' splined ends were almost twisted off (100% street use too) but... the TKO kept up and hasn't missed a beat, once.

I've got the T-56 (version of at least) in my C6 Z06 and I'm a good bit over 500 lb ft at the flywheel (472 rwtq) It's always shifted slicker 'n snot. I do believe the tranny's under rated from the factory..

Dave

[blykins]

I'm sure you're right Dave. In engineering, there are certain things as "safety factors".

The TKO is rated by "continuous" torque, not peak torque. So if you put this thing on a dyno, you could make it hold 600 lb-ft all day long.

There are lots of things that we can do to increase the strength and shifting capabilities of the TKO as well. 700-750 lb-ft is very do-able with some REM polishing and cryogenic treatment of the gears, hubs, etc.

My advice to anyone that's in the market is to drive a car with each transmission. You may like one and not like the other. To me, the best shifting trans is a T5 or a Toploader. But the T5 won't last behind any power and the Toploader is only a 4 speed.

[lal Naja]

Reading this forum is detrimental to your wallet!!!!!

My Cobra is in the build stage and I have installed a Super T-10. Now I'm having second thoughts and it looks like I'm now almost committed to installing a Tremac TKO.

I only have 35 1/2" between the bell housing mounting surface and the diff flange of my Jaguar IRS. My drive shaft will become almost 2" (1.96") inches shorter and it is only about 8" long now.

I haven't seen much mention about hydraulic throwout bearings installed on the TKO. But I have to assume that this is no problem, as I have no space for an external slave.

Keep the flow of info coming.

Thanks,

Arthur

[Excaliber]

I hate those internal throw out bearing assemblies, I'd FIND room for an external slave.

I just ordered the TKO-600 from Blykins myself, I won't take any chances on a weaker trans. I'd like a little taller 1st gear ratio but it's OK. For some reason most folks want a lower one, go figure, you ARE going to have more traction issues with a lower ratio 1st gear.

.8 over drive for me, WAY to much drop with the .6 for MOST of us with a decent cam profile. Trying to keep your motor in the proper rpm range will have you doing 80-85 mph and looking for a ticket. I did my calculations based on a more reasonable 70-75 mph and went .8.

[lal Naja]

Thanks for the advice.

I've tried to do the external slave with the smallest slave I could find. Just not enough room. I even made a custom length fork, custom bracket. Slave gets too close to the header pipe. No room for a bleeder, or even space to run a hose for a remote bleeder. I've read pros & cons on the internal hydraulic unit and I'm willing to take a chance with it.

My Jag rear end is 3.31:1 and the .8 overdrive seems like my choice too.

I just have to figure out what shifter option I need to take. My shifter is 9.5" From the bell housing/trans mounting surface and in IMHO the location couldn't be more perfect & ergonomic!. 7" moves it too far forward, but I can have a shifter stick that bends backward. I have to seriously start making my measurements and see what conflicts I have. The 12.68 shifter location moves it too far back and I don't really like the curved forward look that the original had.

I love the location of my Super T-10 shifter and so I have to come to terms that a new location that may not be as visually pleasing.

Thanks for your comments,

Arthur

[RICK LAKE]

lal Naja Art Have you looked at the super richmond 5 speed? The shift location is in the same place as the trans you have. The trans mount is 1" back of the trans you have. If you are looking to use the orginial shifter, it works nice. If racing I run a short shifter to the trans. This trans is good for the 600/600 rating.