i was actually just doing some research and a couple things stood out.i would say it takes a while to shift into gears.like the other day it wont switch into 4th and i just redlined it driving at 70mph.so could it be a solenoid or sensor?would the trans oil be kinda black from that?
i made my transmissin rebuilt. they replaced everything inside. mine was vibrating during 3rd to 4th shifts. also orings raound selenoids were replaced by them too. not it works like brandnew. it was hesitating to shift up to 4th gear.
i believe you should first check selenoids with a OHM meter to see if they are working ok. majeor three of them should be between 15-40 ohms. then temperature sensor for ATF.