I have a problem where when I first start my corolla on any day, (automatic) it shifts fine through the first 3 gears, and on the 4th or o/d I guess, it hesitates for a while sometimes up to a minute to shift into 4th. it's usually around 65 -70 that i can turn the engine is probably turning 4 grand or something in fourth.. is something wrong with the transmission or does it need the filter/fluid changed?