Sometimes maybe once a day when it shifts it will hesatate before shifting then throws a very hard shift. Fluid is full, think is time for a flush or is there some king of valve that is getting stuck then frees up and that causes such an agressive shift.

 

Well there are a whole lot of valves in a transmission... hense the name valve body.

I'd start with the throttle valve. Try adjusting the TV cable and go from there.

 

theres a rod that goes from the throttlebody to the tranny. get underneath the truck and locate where it attaches to the tranny. loosen the bolt (13mm)and push the lever on the tranny forward as far as it will go, then tighten the bolt.
it's simple and i hope it works for you.