My 1993 W150 5.2l today has started shifting later than it should it seems to shift fine just only after being at a higher rpm for a while. If I accerlate quickly it seems to shift fine then but for normal shifting it shifts late. Also today it started dying if I put it in gear and have the brake on, with out the brake on it doesn't. Its got right under 75k miles and tranny fluid lvls and color look fine. Any clues as to where to start looking.