My service four wheel drive light came on n not shifting good

My service four wheel drive light came on n not shifting good I had my transmission rebuilt and afterwards the car wouldn't start. That's fixed but then it was shifting through all gears before twenty miles an hour, iput anew computer in it and it fixed the sodding problem for aweek, now the service 4 wheel drive light is on and it is not shifting properly, it wants to almost act like you can't give it has at the shift points