# anyone else have problems with the m12?



## taylorb765 (Jun 11, 2010)

Im having problems getting my 06 to go into 2nd and 4th. The car has 55k miles on it and has only made about 10 passes down the track and driving normal otherwise. It does not grind just acts like the shifter hits a block off plate then it slowly falls into gear. I have worked on alot of manual transmissions but never been inside a t-56 could this possibly be a shift rod-detent issue? Before someone asks skipshift has been turned off.


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## 87GN06GTO07IRL (Aug 10, 2009)

Syncros?


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## taylorb765 (Jun 11, 2010)

06gtoin216 said:


> Syncros?


Usually they will grind or pop out of gear this doesnt do either, just goes in hard. Dont really understand it, cant drive it in the winter anyway maybe ill get my first look at the inside of a t-56 but takes so many specialty tools to take them apart. I have changed the fluid with royal purple atf and didnt make a difference.


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## motoristx (Apr 27, 2010)

well, i have an idea... it might not be what your suffering but I've noticed gears hard to get into on mine.

GM put a lot of rubber gaskets and other crap all over that shifter assmblely, this includes some rubber bushing like spacers and a rubber seal on the main shifter plate. when i pulled my shifter plate (about 3 1/2 x 9 in.) i noticed if i tightened down too much it would bind on the shifter rail just under the plate. if i loosened it up, it would leak but i could shift easy...

the way you can tell if this is happeneing is pull all that shifter crap out to get to the plate and shifter rail, and look at the bottom of the plate and see if it shows signs of rubbing. this is a bit of a pain, but you can get to it from the inside of the car by removing the center console plastic (be prepared to ask a friend for help with that white rubber boot).

my fix: 
-buy the B&M short shifter
-buy a T6 plate of aluminum about 3.5 x 6.5 in and .5 in thick
-take the original plate to a machine shop and have them match up the 4 bolt holes for use without the rubber spacers. Machine out the shifter hole at the lager diameter, and finally, drill and tap the 2 hole in the back for use with the B&M short shifter.
- - this will seal it up nice and tight, give you extra space for the shift rail (about 1/8 in) but it will be a lot louder then stock due to pulling out all the rubber stuff.

alt fix: 
-take your original shifter plate to the machine shop and have the oval part (where the shift rail is rubbing) milled out about 1/16 - 1/8 in. keep in mind, it's kinda thin right there so you can't mill very much...
- - this will allow you to keep all your stock shifter "crap" and allow for a quieter ride due to all the original rubber sound dampening material

has anyone else tried this?


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## B-ville Goat (Oct 5, 2008)

Aftermarket shifter, new fluid(I use Royal Purple SynchroMax), and bleed the hydraulics on the release system and you will be good, probably mostly needs bled.


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## 20GTO06 (Apr 16, 2010)

I have experienced some of what you are. My shifter periodically gives me problems when i go from 1-2; but I usually drive 1-3 anyways. I plan on doing a fluid change in the spring time. This car has one of the roughest shifters I have ever driven.


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## taylorb765 (Jun 11, 2010)

B-ville Goat said:


> Aftermarket shifter, new fluid(I use Royal Purple SynchroMax), and bleed the hydraulics on the release system and you will be good, probably mostly needs bled.


I have royal purple in it, i have changed the brake bluid and bled it, doesnt seem to be a disengagement issue. I replaced the shifter with a billet pro and have gone back to the stock one cause of all the noise. No idea what it is thinking im going to tear it out for the winter and see whats goin on I have to replace the clutch anyway cause its starting to make a loud clunk when it engages.


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