rattt g

we just took apart an 08 rear that broke at the track, and we found out that there was no clutch pack in there just the spider gears, come to find out only the t56 cars have the clutch pack rears

3LZZ06

Hmmm...

This is news to me as well, I thought I had heard of some early 08's having the clunking in the rear due to the clutch packs and the updated rear lube cured the problem.

I could be mistaken though...

PhysiPhile

If there isn't a huge difference, then why did GM make the change? Why not just wait till the next generation. Changing transmissions gives the perception that the old one's were flawed.

3LZZ06

I believe the development of the new TR6060 was for the upcoming ZR1 which was in need of a more robust transmission. The whole Corvette line just happened to be recipients of the update.

Burnin4

Ive owned an 06 and an 08....I wont own another pre 08 Z, mosty for the total package not because of the t56.

Rock36

Well one major reason for the change is the sheer volume of new cars that have a TR-6060 in them already. This volume alone would dictate the corvette make the transition to a TR-6060.

TR-6060 can be found in:

2007+ Mustang Shelby GT500
2009+ Dodge Challengers
2009 Pontiac G8
2009+ CTS-V
2010+ Camaro SS
2008-2010 Dodge Vipers
and probably a few others...


The TR-6060 is a better transmission, no arguement, just not THAT much better. And it certainly doesn't mean the T-56 is crap or prone to failure. It is just an updated new transmission. It isn't like the T-56s are falling apart.

If my sources are correct. The TR-6060 is rated for 600 ft-lbs, and the T56 is rated to 550 ft-lbs. Both substantially strong enough to handle stock and modified Z06s. Other differences or improvements over the T56 are:

- Reduced friction in the shifter system courtesy of a new cam and anti-friction plunger to control the side load shift detents.

- Forward and rearward shift detent grooves are broached on the front of the main-shaft with a spring-loaded anti-friction roller, for more precise control of shift detents and positive shift feel.

- Anti-friction ball struts, sintered hubs and fine-pitch splines on all synchronisers for reduced friction between components - delivering improved shift feel and reduced shift efforts.

- Wider, two piece gears with machined clutch teeth for more precise gear engagement and reduced potential for gear block-outs."


Again, based on the OPs question. He decided that his budgets fits getting a 2007, and there is no reason IMHO that the T56 should be a deal breaker if a 2007 fits his budget. The T56 is still a good transmission, it just isn't the newest transmission.

FWIW, and someone correct me if I am wrong, but the TR-6060 is some 40lbs or so heavier than a T56.

0TJ@RPMtransmissions

06 Z06 differentials have "spider gears" and bronze clutches

07 up Z06 differentials have "spider gears" and carbon cluthes

09 and up Z06 differentials have the cooler pickup fitting in a new location

those are all the differences...

if you took a differential apart and it had a "torque biasing" differential, which is what I believe you are trying to say, it was installed aftermarket.

160KTS

Your information is great, finally someone who gets it. You shouldn't be afraid of having a T56. I'm going to throw a cam in my already 500whp Z and quite literally the transmission (and engine) are the last things I am worried about breaking. And of course there are slightly different parts than the T56 from your 98 Fbody or your SVT Cobra.

And yes, I do believe they are physically heavier too.

MTIRC6Z

Would the ZR1 differential have the same carbon clutches as the Z06?

Which pieces in the ZR1 are billet vs. the forged pieces in the Z06?

Lastly, when you do your L-5 treatment on a ZR1 differential, do you change the clutches?

Oh, and that "cooler pick-up fitting in a new location" sure makes it PITA to put a ZR1 differential in an '08 or earlier Z06, particularly when you don't notice the difference until you go to slam everything back together

Cheers, Paul.

NORTY

the T-56 should handle your car w/100 shot easily. You might take a look @ your clutch setup however...

NORTY

Liter bike riders laugh at this... (They do 100+ in first...)

0TJ@RPMtransmissions

The ZR1 has the same carbon clutches
They have different part number springs

The aluminum and steel parts of the center rotator are billet

The spider gears are 4340

we use the ZR1 clutches in the stage 3 ZR1 differential builds

The ZR1 pinion support is stronger as well

TAILWAG

I have owned an 06 and 08...I have had problems with both transmissions, however, I prefer the feel of the 08.

soroZ

so stock the z06 has low 400ft lbs of torque and the tranny is rated to only handle 550? so with a 100 shot and some boltons and maybe a cam I would have to replace the trans????????
Also is the differential different in the various years? if so is it that big of an improvment.

FastestBusaAround

Ya, but we can rev 'em to 14K and need to hit 100+ in 1st - my '05 ZX10R used to do almost 109 in 1st (NOT GPS verified) --

Bill Dearborn

This is the description of the diff in the 08 models. I got it from the Service Manual.
Getrag Differential


The vehicle is powered by either the LS3 or LS7 V8 engine. Motion is transferred from the engine crankshaft/flywheel through the driveline support, propeller shaft, assembly to either the 6L80-E (MYC) automatic transmission or the Tremec 6-speed manual transmission. The splined output shaft of the transmission drives the pinion, which in turn, rotates the ring gear and differential case assembly. The limited slip differential distributes torque/power to the rear wheels via individual axle shaft assemblies. The limited-slip differential is of a conventional separator plate and friction disc type design.
The differential housing, side covers, pinion housing, and differential case halves are constructed of cast aluminum. The internal components incorporate a hypoid gear set, ring and pinion, carrier assembly, and pinion housing assembly. The pinion is supported in a pinion housing by tapered roller bearings. The pinion is positioned rearward of the ring gear centerline.
Pinion position, ring gear position, and carrier bearing preload are determined by shimming procedures.
Each ring gear has specific setup dimensions, A1 and A2 values, stamped onto the side area of the gear. The A1 and A2 values are unique to each ring gear/pinion and are determined during the manufacturers gear/pinion noise and vibration setup and testing. The vehicle speed sensor, in manual transmission applications, detect the rotational pulses produced by the ring gear teeth and send the signal to the vehicle control module (VCM).
The differential assembly is available in 2 gear ratios. The 3.42 ratio axle is used in all manual transmission applications. The 2.56 ratio axle is standard equipment for automatic applications.
Some models have a differential lubricant pump and cooler. Oil is pulled from the sump through an external oil pipe into the pump. Oil is pumped through an external oil pipe to the cooler. The oil is cooled by dissipating heat with transmission oil returning from radiator mounted cooler.

The illustration that goes with this description clearly shows the clutch packs.

Bill

rattt g

do you have the link to that illustration? the rear we took apart
had no clutches, and the shop that is fixing it said 08 and up
are not the same as 06-07

160KTS

No, you don't have to replace your transmission. I personally know cars well over the horsepower range (and weight) on a stock t-56. Your clutch will take a poop long before your transmission even considers it. I am going to put in a cam, in addition to my bolt-ons, and maybe spray. But I also run slicks at the track which woudl cause way more stress. Again, I'm not worried about the trans, I'm worried about the clutch. You should be too. Trans = no breaking. Don't think about if you havea t56 or a tr6060 just remember regardless of which one you have, you have one of the best transmissions built. they will handle whatever you want to throw at them.

BADZ

With my power, my t56 is holding 850+ rwhp and about the same amount of tq.

No problems at all.

Autobahn93

It is probably not a fair comparison but I have just up-graded my T56 to a TR6060 Level 6 from RPM (Thank you Jeremy for the great support and advice) and all I can say is "WHAT A HUGE DIFFERENCE"
It shifts so much smoother and faster than my old T56. I mean I never really had an issues with the T56 but now the shifting is noticeaby shorter and much more acurate. Also no more problems getting the rear gear in when backing out of my garage

PS: I also got the special gearing 5th (.8) and 6th (.63) and I really like it. As I just got my car back today I will report more when I have put some more miles on it.

I love this new transmission!