Dwayne78

I would definitely take the pan off the transmission, a lot of times these part time mechanics will leave the old "O RING" or seal in the transmission because sometimes they don't come out with the screen and stay in so when they put the new screen in it doesn't create a air tight seal so it sucks air and fluid does not get where it needs to go. I would check that first of all. And Lucas transmission stabilizer helped a few of my transmissions . Hope this helps.

My 2011 GMC SIERRA DENALI has the 6.2 and my transmission got to the point it was doing the exact thing I took mine to BIG DAWGS TRANSMISSIONS and my clutches and some valve bodies were sticking. Fixed it in 1 day had it back 24 hours later $1100 it helps when you know the owner and you do a lot of welding and fabrication for them as well. There is also a valve body on that transmission you can tighten or loosen the control how smooth she shifts or how fast and hard you want it to shift as well, all depends on the way you turn it and how you like it. I do a lot of pulling so mine shifts fast and hard with a built transmission and new hardened gears I'm ready to pull the world on faster circles