started with a shuddering noise when under a light/medium load and shifting from 2nd to Drive, and turning right.
got to the point it would shudder 2nd to drive on straight line
Now shudders under medium load in low gear to 2nd shift
Local shop (Corvette Connection here in Ft. Myers) said the 2nd-3rd(drive) plates are the smallest ones and the easiest/first to fail. Problem stems from the TCC, and cars generally being driven with shifter in OD, then TCC release fails, and well the rest is history. He recommend do not used OD, or shift it manualy, and allow the TCC to stay disengaged, harder on gas mileage, but easier on trans.
And yes i highly recommend a full flush, and filter change, assuming your trans is still mechanicaly sound, it will smooth out the shift, and get the residual crap out of the system.
Any reputable Quick lube place is more that capable of doing it, Plus you can stand about 4 ft away and watch (keep an eye on)them, and not be told to leave .