The 3-4 piston is the most common failure of a 4L60E. Which will burn up the 3-4 clutch pack. According to the videos I’ve been watching.
I currently have that problem as well in my 2000 S10 4 wheel drive pickup.
I am going to attempt to change the 3-4 clutch pack and 3/4 piston alone as well as the TCC spring upgrade.
If you are mechanically inclined and watch videos of the transmission teardown you will be able to see how to do this, it’s fairly easy once you get it on the bench.
I will try to remember to post how it goes.