weird shift????


i went to a local junk yard and bought a tranny when i got it home i noticed the outer splines were wore allmost all the way i took the pump out of my gn tranny and changed the hole problem iswhen i first put the car in gear and take off it will start out in first and shift up to third it will not go into overdrive unless i am doing about 90 under that it will go in if i let off totaly on the gas but as soon as i push on the gas it jumps right when i come to a stop sign and go to take off it will start out in second gear does anybody have a clue:confused: :confused: :confused: :confused: