T56 transmissions
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
T56 transmissions
Hello everyone I own a c5 z06 (2002) and when I call around to see who can rebuild my transmission, everyone is telling me they only replace it with a new one, because the parts needed to do a rebuild are no longer made.
well, if that really is the case, what all should I be looking to have them replace to save myself a trip? I know a little but not a lot.
can someone list me everything needed?
obviously the T56 transmission, but should I also purchase a new clutch, or torque tube, do I need a torque converter? Or is that just for autos? Thank you. Also, does no one really rebuild these anymore? I am in northern California
well, if that really is the case, what all should I be looking to have them replace to save myself a trip? I know a little but not a lot.
can someone list me everything needed?
obviously the T56 transmission, but should I also purchase a new clutch, or torque tube, do I need a torque converter? Or is that just for autos? Thank you. Also, does no one really rebuild these anymore? I am in northern California
Le Mans Master
Joined: Sep 2017
Posts: 5,232
Likes: 1,529
From: Pasadena, MD
2023 C5 of the Year Finalist - Modified
You can have someone pull and replace the trans with a beefier trans from RPM. You probably want to replace the slave, master and install a remote bleeder. I would find a corvette specialty shop in your area if you have one.
https://rpmtransmissions.com/product...ns/tremec-t56/
https://rpmtransmissions.com/product...ns/tremec-t56/
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
You can have someone pull and replace the trans with a beefier trans from RPM. You probably want to replace the slave, master and install a remote bleeder. I would find a corvette specialty shop in your area if you have one.
https://rpmtransmissions.com/product...ns/tremec-t56/
https://rpmtransmissions.com/product...ns/tremec-t56/
thank you. Yes I did try to call my corvette shop just one city over but they told me they no longer perform any kind of work on C5 transmissions… replacement or rebuild.
they referred me to a Chevy dealer in Rio vista to have the work done, and the Chevy dealer recommended a T56 from RPM transmissions. I just don’t wanna throw in a new transmission with no other supporting parts.
Melting Slicks
Joined: Mar 2006
Posts: 2,754
Likes: 380
From: South Florida FL
for starters, why are you doing this? what is your trans doing/not doing?
most quality rebuilders will disassemble, see what failed, and address it accordingly. Yes parts are hard to find, but they're talking about the major parts, like a gears/shafts etc, the parts what typically fails like synchros, pads, forks are availability. https://www.thegearbox.org/T56_corvette.html carries most of these parts.
as for maintenance things to do while you're there, is the torque tube bearings and couplers, clutch, new oem slave cylinder and add a remote clutch bleeder.
most quality rebuilders will disassemble, see what failed, and address it accordingly. Yes parts are hard to find, but they're talking about the major parts, like a gears/shafts etc, the parts what typically fails like synchros, pads, forks are availability. https://www.thegearbox.org/T56_corvette.html carries most of these parts.
as for maintenance things to do while you're there, is the torque tube bearings and couplers, clutch, new oem slave cylinder and add a remote clutch bleeder.
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
for starters, why are you doing this? what is your trans doing/not doing?
most quality rebuilders will disassemble, see what failed, and address it accordingly. Yes parts are hard to find, but they're talking about the major parts, like a gears/shafts etc, the parts what typically fails like synchros, pads, forks are availability. https://www.thegearbox.org/T56_corvette.html carries most of these parts.
as for maintenance things to do while you're there, is the torque tube bearings and couplers, clutch, new oem slave cylinder and add a remote clutch bleeder.
most quality rebuilders will disassemble, see what failed, and address it accordingly. Yes parts are hard to find, but they're talking about the major parts, like a gears/shafts etc, the parts what typically fails like synchros, pads, forks are availability. https://www.thegearbox.org/T56_corvette.html carries most of these parts.
as for maintenance things to do while you're there, is the torque tube bearings and couplers, clutch, new oem slave cylinder and add a remote clutch bleeder.
In short, I’ve lost the ability to upshift and downshift into 3rd gear if I need more than 3.5k rpm’s. The car will stay in 3rd if I go in before 3K rpm’s, but if I try to put it in 3rd with more than 3.5K RPMS, the stick will jump back out into neutral. Also 4th gear grinds no matter the circumstances. It’ll stay in gear tho.
I called my local Chevrolet corvette shop, as well as a Chevy dealer nearby, and both told me rebuilds were no longer possible. Partly why I’m here because I am wondering if they are bullshitting me? Also I wouldn’t expect myself to be capable of working on my own manual transmission rebuild. I’ve only ever changed basic parts.
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
Well this greatly helps since it would seem I just need the 3-4 synchronizer kit, but now I’m wondering how hard a job this is? I’m guessing pretty difficult?
Racer
Joined: Mar 2015
Posts: 415
Likes: 284
From: Indianapolis
If you're mechanically minded, go for it. If not, might be best to hand it off to someone else
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Pro
Joined: Apr 2018
Posts: 563
Likes: 201
From: Montgomery City, MO
Just to jump in w/ some addl info - if you still have the original M12 transmission, hard parts like gears may not be too easy to find. And unfortunately it sounds like you might need a new 3rd.
May be worthwhile investigating if you still have the factory M12 or if it's been replaced with a more commonly available MN6.
These transmissions aren't difficult to rebuild relatively speaking. Getting the trans / diff / torque tube out of the car is far more logistically challenging. But you will need some specialized equipment to rebuild the trans properly. It's not impossible, but also not something you want to cut corners on. There are plenty of users that would be willing to give pointers, myself included.
The gears for the M12 are the main parts that are no longer available for these. All the other parts are identical to the MN6 (synchro frictions, blockers, sliders, keys, shift fork pads, output shaft, etc.). Everything you would need for a MN6 is available at thegearbox.org and / or txdrivetrain.com. If the output shaft needs to be welded back to correct O.D., TDP is supposedly the place to go for this as well.
May be worthwhile investigating if you still have the factory M12 or if it's been replaced with a more commonly available MN6.
These transmissions aren't difficult to rebuild relatively speaking. Getting the trans / diff / torque tube out of the car is far more logistically challenging. But you will need some specialized equipment to rebuild the trans properly. It's not impossible, but also not something you want to cut corners on. There are plenty of users that would be willing to give pointers, myself included.
The gears for the M12 are the main parts that are no longer available for these. All the other parts are identical to the MN6 (synchro frictions, blockers, sliders, keys, shift fork pads, output shaft, etc.). Everything you would need for a MN6 is available at thegearbox.org and / or txdrivetrain.com. If the output shaft needs to be welded back to correct O.D., TDP is supposedly the place to go for this as well.
Melting Slicks
Joined: Mar 2006
Posts: 2,754
Likes: 380
From: South Florida FL
I called my local Chevrolet corvette shop, as well as a Chevy dealer nearby, and both told me rebuilds were no longer possible. Partly why I’m here because I am wondering if they are bullshitting me? Also I wouldn’t expect myself to be capable of working on my own manual transmission rebuild. I’ve only ever changed basic parts.
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
so basically what you’re saying is, I need to either learn how to do it myself, or ask around/find someone in the area willing to do it… damn, lol.
Drifting
Joined: Dec 2009
Posts: 1,320
Likes: 58
From: Benicia CA
Check out texas drivetrain performance. Freight shipping is not too bad. I've dealt with them a bit and I'm always impressed.
I was going to rebuild a used one i bought but it needed too many parts replaced. Instead i bought a rebuilt unit from them and sent my used one for a core refund. Its also a good time to build your diff too since its the same shipping cost.
I also plan to rebuild the t56 that came out of my low mileage car eventually. It doesn't seem too bad to do, but its common to need more parts replaced than you think.
I was going to rebuild a used one i bought but it needed too many parts replaced. Instead i bought a rebuilt unit from them and sent my used one for a core refund. Its also a good time to build your diff too since its the same shipping cost.
I also plan to rebuild the t56 that came out of my low mileage car eventually. It doesn't seem too bad to do, but its common to need more parts replaced than you think.
Thread Starter
Heel & Toe
Joined: Feb 2024
Posts: 17
Likes: 1
Check out texas drivetrain performance. Freight shipping is not too bad. I've dealt with them a bit and I'm always impressed.
I was going to rebuild a used one i bought but it needed too many parts replaced. Instead i bought a rebuilt unit from them and sent my used one for a core refund. Its also a good time to build your diff too since its the same shipping cost.
I also plan to rebuild the t56 that came out of my low mileage car eventually. It doesn't seem too bad to do, but its common to need more parts replaced than you think.
I was going to rebuild a used one i bought but it needed too many parts replaced. Instead i bought a rebuilt unit from them and sent my used one for a core refund. Its also a good time to build your diff too since its the same shipping cost.
I also plan to rebuild the t56 that came out of my low mileage car eventually. It doesn't seem too bad to do, but its common to need more parts replaced than you think.
Supporting Vendor
Joined: Apr 2011
Posts: 3,332
Likes: 195
From: Frederick Maryland
St. Jude Donor '08-'09-'10-'11-'12, '14-'15-'16-'17-'18
Hello everyone I own a c5 z06 (2002) and when I call around to see who can rebuild my transmission, everyone is telling me they only replace it with a new one, because the parts needed to do a rebuild are no longer made.
well, if that really is the case, what all should I be looking to have them replace to save myself a trip? I know a little but not a lot.
can someone list me everything needed?
obviously the T56 transmission, but should I also purchase a new clutch, or torque tube, do I need a torque converter? Or is that just for autos? Thank you. Also, does no one really rebuild these anymore? I am in northern California
well, if that really is the case, what all should I be looking to have them replace to save myself a trip? I know a little but not a lot.
can someone list me everything needed?
obviously the T56 transmission, but should I also purchase a new clutch, or torque tube, do I need a torque converter? Or is that just for autos? Thank you. Also, does no one really rebuild these anymore? I am in northern California
__________________
Safety Car
Joined: Mar 2017
Posts: 3,771
Likes: 940
From: Orlando Florida
There is a series of videos on the youtube of a complete rebuild, including removal, reinstallation, and test drive. 14 rebuild videos and 1 new parts video. Most in the 20 to 30 minute range, 4 hours in total -- but he doesn't skip much.
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Sorry to be reviving an old thread, but I've been searching everywhere looking for recent mentions of AMP distributing. Id never heard of them until I started my t56 rebuild. Its great to see someone from a familiar forum post this. Are they any good? Their prices on some of these things seem almost too good to be true.
Le Mans Master
Joined: Jul 2010
Posts: 6,013
Likes: 726
Sorry to be reviving an old thread, but I've been searching everywhere looking for recent mentions of AMP distributing. Id never heard of them until I started my t56 rebuild. Its great to see someone from a familiar forum post this. Are they any good? Their prices on some of these things seem almost too good to be true.
You dont want to do this twice.
Last edited by helga203; Dec 9, 2025 at 12:34 PM.
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Because it is. Buddy order gears from them and they were out of spec when he measured them. Thank god for Ebay to step in and get his refund., He had to fight tooth and nails beq ause they said "as is" Why would you sneak that in there. And ebay took them off there site. They probably changed their name to another company to find a lope hole. Stick with the the reputable companies.
You dont want to do this twice.
You dont want to do this twice.