Thread: M12

**Texas Jack** · 11-08-2008, 04:36 PM

Noticed today while working on the car the trans was shown as an M12, I looked it up and the ratios are different, do all GTO's come with that and we call then M6s, anyone know. Thanks

**Benner** · 11-08-2008, 04:48 PM

m6 simply means 6 speed manual. I believe m12 was used on all manual gto's

**Sarge** · 11-09-2008, 05:00 AM

Well there are 4 different T56 slush boxes GM has...
SIX-SPEED MANUAL TREMEC T56 (MM6/MZ6//M10/M12) CAR TRANSMISSION
The M12 is the beefed up trannie...some of the additional features found in the M12..
• High-density carbon blocker rings (M12)
• Stronger snap rings on synchronizer hub (M12)
• Carbon reverse synchronizer (M12)
• Revised shift precision (M12)
Stepped clutch teeth on synchronizer sleeves (M12)
Stepped clutch teeth on the synchronizer sleeves are now added to the LS2-powered CTS-V application. 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.
High-density carbon blocker rings (M12)
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. 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.
Originally, the Tremec T56 evolved as a higher-torque capacity, six-speed version of the proven M49 five-speed manual transmission, and was introduced in the 1993 Chevrolet Camaro and Pontiac Firebird. It was also added to the 1997 fifth-generation Corvette.
Further applications included high-performance models, such as the Cadillac CTS-V in mid-2004, which used the 400-horsepower LS6 engine mated to the M12 version of the six-speed, and the Pontiac GTO, which used the 340-horsepower LS1 engine with the M12 but with a higher ratio fifth gear to maximize acceleration in that gear.
The sixth-generation Corvette with Z51 option uses the MZ6 version of the six-speed, with ratios from the M12, which are higher ratios in first, second, and third gears than the MM6, which is the standard gearbox, as well as a lower-ratio fifth gear to increase top speed in fifth gear with the 400-horsepower LS2 engine.

**Texas Jack** · 11-09-2008, 05:21 AM

Sarge you must type 500 WPM, thanks' for the info. Makes me happy to know I have that. So that is rare in the GTO or not? Many thanks

**Texas Jack** · 11-09-2008, 05:24 AM

Damn you said it is in your right up, need more coffee!

**Sarge** · 11-09-2008, 06:03 AM

Originally Posted by Texas Jack

Sarge you must type 500 WPM, thanks' for the info. Makes me happy to know I have that. So that is rare in the GTO or not? Many thanks

LOL...no some is cut and paste...I aint typing all that shit

The M12 is a beefy trannie..that is the bottom line....all GTO's have 'em.

**Texas Jack** · 11-09-2008, 06:07 AM

Thanks' buddy!!!!!!!!!!!!

**pmolina0436** · 11-09-2008, 05:55 PM

: ( i have an A4 so good though ...i hope

**pmolina0436** · 11-09-2008, 05:59 PM

Originally Posted by Sarge

LOL...no some is cut and paste...I aint typing all that shit

The M12 is a beefy trannie..that is the bottom line....all GTO's have 'em.

Of the topic sarge!!!but i read other post from you and you seem like you dont like the idea off some quick HP!!im talking about N2O!! Why??? I mean if your running a 50-75hp shot isnt it safe? Well im just wondering why your not a fan of n20

texasjack sorry i didnt mean to change your topic on this thread!! I just need to KNOW!!

**Texas Jack** · 11-09-2008, 06:35 PM

No big deal.

**pmolina0436** · 11-09-2008, 07:04 PM

Originally Posted by Texas Jack

No big deal.

ay tj are you into n20...damn im really thinking about adding a 50 or 75 shot..It seems pretty safe, im reading on the ZEX nitr. system..what you think

**Texas Jack** · 11-09-2008, 07:19 PM

No way!!!!!! Regards

**Sarge** · 11-10-2008, 03:09 AM

Originally Posted by pmolina0436

Of the topic sarge!!!but i read other post from you and you seem like you dont like the idea off some quick HP!!im talking about N2O!! Why??? I mean if your running a 50-75hp shot isnt it safe? Well im just wondering why your not a fan of n20

texasjack sorry i didnt mean to change your topic on this thread!! I just need to KNOW!!

LOL....No I am not a N02 fan. Way too many variables to blow you up. Tunes/solenoids going away (which happens a lot)/valves clogged/bottle pressure on and on. And of course the constant refilling of the bottles....and is my bottle pressure up and my system on as some butt monkey revs on you at the light. Nope.....for 75RWHP I'll take an always on and ready cam/heads car

**pmolina0436** · 11-10-2008, 05:33 AM

Originally Posted by Sarge

LOL....No I am not a N02 fan. Way too many variables to blow you up. Tunes/solenoids going away (which happens a lot)/valves clogged/bottle pressure on and on. And of course the constant refilling of the bottles....and is my bottle pressure up and my system on as some butt monkey revs on you at the light. Nope.....for 75RWHP I'll take an always on and ready cam/heads car

makes sense

**TLS_Addict** · 11-10-2008, 01:14 PM

I was under the impression the ratio's in the F-body were different from the GTO/C5? The GTO does have the same internal ratio's than those in the C5. Are the ratio's not slightly steeper in the C5 and GTO than those in the F-body?

**Texas Jack** · 11-10-2008, 04:14 PM

TLS Look at Sarge's post above and see if that helps.

**pmolina0436** · 11-11-2008, 11:26 AM

Originally Posted by Sarge

LOL....No I am not a N02 fan. Way too many variables to blow you up. Tunes/solenoids going away (which happens a lot)/valves clogged/bottle pressure on and on. And of course the constant refilling of the bottles....and is my bottle pressure up and my system on as some butt monkey revs on you at the light. Nope.....for 75RWHP I'll take an always on and ready cam/heads car

off topic again sorry!! Sarge i was looking at the pics on your car!! where you get them front grills at??? they look nice on the goat!!