Implala 3,8 hesitates changing gears, rpm rise let foot off gas rpms drop, gears shift.

Im Almost possitive it is the transmission with out a dought. Like someone els stated it has jerking and hesitation . This isnt all the time though. For weeks it wont do nothing, but then for mabye a few days it will. Also the speed meter jumps all over when this problem occurs. I juss ha my car fixed for the intake manifold gasket,valve cover gaskets, some other manifold was fully replaced. Cost was about $600 rounded up. I still need to replace the hub assembly. Im sick of it.

Most mornings when I leave my driveway going uphill for the first time each day, the Transmission shudders quite badly. This has also happened 1 time when fully warmed up & on level ground, turning at an intersection. Last two fluid & Filter changes were at 160k & 135K miles - recommended intervals prior to that. Last change upgraded to the new GM trans fluid.