transmission problems

my truck is a 2002 avalanche with the 4l60e and it started missing shifts or sometimes it wouldnt shift at all. I was told to replace the filter and it helped a bit but it still wont shift right it will rev up real high and wont shift until i let go of the gas. Im thinking it might be the shift solenoids. Or is the transmission crapping out? Any input or suggestions as to what might be the problem is highly appreciated.

Well....what did you find in the bottom of the pan when you pulled it to change the filter.

Speed sensor can make it act goofy too

i was suprised to find nothing in the pan. i will look into the the speed sensor.