Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters

T56=m12?

Thread Tools
 
Search this Thread
 
Old May 27, 2008 | 04:14 PM
  #1  
TransAm Mania's Avatar
Thread Starter
On The Tree
iTrader: (7)
 
Joined: Aug 2006
Posts: 161
Likes: 0
From: Cicero IL
Default T56=m12?

So is the M12 the same thing as a T56 but with different gears? Is there anything different about the shifter? I'm looking for a 6 speed for my 79 T/A conversion and found an M12 for $2,000 that I can pick up.
Reply
Old May 27, 2008 | 04:33 PM
  #2  
connexion2005's Avatar
12 Second Club
iTrader: (49)
 
Joined: May 2006
Posts: 966
Likes: 0
From: College Station, Texas
Default

3rd and 4th gear have different ratios from what I understand. I'm not sure on the input shaft length from the GTO's though...
Reply
Old May 27, 2008 | 04:37 PM
  #3  
melchoir's Avatar
12 Second Club
iTrader: (4)
 
Joined: Sep 2005
Posts: 589
Likes: 0
From: Fort Myers, FL
Default

1,2,3,5,6 have different ratios.

MN6 T56 and M12 T56
1st 2.66 2.97
2nd 1.78 2.07
3rd 1.30 1.43
4th 1.00 1.00
5th 0.74 0.84
6th 0.50 0.56

Also the M12 has carbon blocker rings and triple cone syncros. All in all the M12 is a better unit, but make your rear end gearing choices accordingly.
Reply
Old May 27, 2008 | 11:19 PM
  #4  
ae13291's Avatar
Banned
iTrader: (8)
 
Joined: Jun 2007
Posts: 3,093
Likes: 1
From: san fernando valley, california
Default

arent all the new tranny rebuild kits carbon blocker rings now?
Reply
Old May 28, 2008 | 12:32 PM
  #5  
greysteel_M6's Avatar
TECH Resident
15 Year Member
iTrader: (5)
 
Joined: Dec 2006
Posts: 871
Likes: 1
From: DFW
Default

06' model summary

Stepped clutch teeth on synchronizer sleeves (M12)
These staggered teeth sequentially engage the gears, which makes engagement feel lighter and more positive to the driver. This modification originally appeared on the 2005 Corvette. -this revision is speaking of the CTS-V
High-density carbon blocker rings (M12) -the first carbon blocker rings were introduced in 02'
More durable carbon friction material is used on the synchronizers.
Stronger snap rings on synchronizer hubs (M12)
For the first-second gear hub, a stronger snap-ring is used to increase durability.
Carbon fiber reverse synchronizer (M12)
To reduce efforts to engage reverse, the synchronizer friction surface is changed to a carbon fiber material. (was brass) Reverse-inhibit mechanism to block the shifter from going into reverse when the driver is aiming toward fifth or sixth gear gate with the shifter is also modified to make it easier to engage reverse.
Revised shift precision (M12)
Tolerances for the shifter mechanism for the Cadillac CTS-V application have been tightened to make the shifter feel more precise.

I believe the M12 was introduced for the 01' Z06, it's a slight step up
Reply




All times are GMT -5. The time now is 10:22 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE