im not pleased with my m6 it broke about a year ago and i had everything replaced that was broke with aftermarket upgraded stuff from a great place ! now i was enjoying my driving experience this evening when i go to 3rd i heard a little grind no big deal right we've all heard it before but now every time i shift into 3rd it does the little grind.its the syncro right? its not hesitant to go goes right in and stays in but that little grind is really annoying after spending that much money on it ! so my question is is the t56 a weak trans? can it handle mid 400hp abuse everyday or should i swap in auto?ive got a great auto guy 45 min from my home my manual guy is 9hr one way from my home!thanks for any info/feedback!!!!!

 

Mine has 80K on it with no problems. You could have a bad one. Honestly, I have heard nothing but good things about this tranny.

 

The T56 is a bad azz transmission but you need to keep your clutch in good working shape along with using a good after market shifter like the Pro 5.0 .

 

i have the pro 5.0 shifter w/ bump stops!

 

M6 awesome tranny, cluth design leaves a lot to be desired compared to other applications..

 

Forgetting the clutch itself, though...how much power are the gearboxes known to handle? And how many miles are they known to have on them(just the gearbox), before failing?

 

i believe the stock T56 can handle 400-450 foot pounds of torque of daily abuse

 

these trannys are fairly tough. what is wrong with yours is the syncro blocker ring is worn out. the syncro blocker rings job is to slow down the gear so that it will not grind going into gear. when it wears out you get the grinding noise you are referring to. did the guy that rebuilt the tranny replace all of the blocker rings or just the ones that were bad at the time? with the right parts a t56 can handle a lot of abuse