I did the expensive oil change this weekend but no luck. I still get hard downshift from 2nd to 1st and a slip sometimes from 3-4th. I also noticed that when I drive at 80km/h and go in N then back to D sometimes I get a hard push, like a hard downshift and then it's ok. Sometimes it's normal, I move from N to D back and forth with nothing other than the rpms moving to the right speed.
Could this be a symptom of a valve body problem and a Valve Body Kit will save me or I should look for a TC and full transmission rebuild kit. I feel like the tranny controller does not change the gear at the matching IN/OUT speeds. Could be a sensor or something?