Im looking at replacing my 4l60E trans in my 09 silverado. It has a 4.8 and i was wonder if i replace the transmission would i have to have a tune or a reprogram? I was told it runs off the PCM so there is no programing needed. im looking for info to know if i need to do a reprogram or relearn. Its shifting hard on pulls and slips on full thottle. Has 260k miles on it. Any info would be nice.