I spoke with a gm trans engineer today, he seems to think it could be the pcs solenoid that actually controls the line pressure, or possibly a bad ground that would affect the operation of all the electrics which controls all of the trans functions. He says normally you will have some symptoms that indicate the end is near like slipping/not going into gear right away/late or no shifts/noise. The pump whine is most likely a clogged filter with clutch mud, it seems to make sense. My first plan of attack will be to pull the pan and see, if there is any metal or other hateful debris if not, I will go ahead and replace the solenoid. I won't be able to do this right away as it is hunting season and I am going north for 10 days. I sure hope he is right. Being most of the miles on the car are highway the trans was not really abused that is why I feel it isn't or shouldn't be terminal. He also said when they did durability the average failure was well into the 200's on a accelerated schedule. I will be sure to let the outcome be known. Thank-you for your input.
