thanks for all the new info do think that i have the same problem as you talked about above. i have a 1990 s10 4x4 with 4.3 motor. it shifts great but then starts to slip in 3rd and over drive almost as if its in neutral but if i shift it to 2nd gear then back to drive it works then starts to slip again and only revs when i give it gas so i shift it down by hand again to 2nd and back to drive it works for a few then it does the same thing like its not in gearthe fluids good not burnt and all gears work fine just acts like its going in and out of gear can you give me any clue what may be the problem with it buddy