I just filled an almost empty transmission in my 4.0 6cyl 4spd auto 04'. When accelerating I feel it down shift ok. But rpms climb to 2500-3000rpms then drop only about 1-200rpms and at about 43-45mph rpms drop to 1500 . Is this normal? I feel it's not. I drive a lot . Just honestly never paid attention. Bleh.