I have a 2002 dodge dakota 4x4 quad cab with a 4.7l v8 in it, I just put a motor in the truck from a 2000 dodge durango 4x4 with a 4.7. I seized the the old motor, after replacing the motor which runs great i get no engine codes starts right up and goes, now the transmission doesnt shift right. reverse neutral and park are all fine, i can shift it into 1st manually then into second manually and into third manually, but no over drive. also if i start from drive it engages then after moving about 5 feet theres nothing it acts like its in neutral, if i come to a stop still nothing until i shift it back to neutral or park then back to drive, once it pops out doesnt matter how high i rev the engine it does nothing, however if i pull the transmission position sensor fuse it will go into drive and move fine but doesnt switch gears, and also seems like its confused on when to down shift. I have replaced both speed sensors in the transmission and the speedo sensor in the rear diff, no change. not sure what im missin here, I dont think its an internal problem as much as a sensor or the TCM not knowing what the hell is goin on with the transmission.
I would appriciate any input on this subject oh also the trouble codes im getting are p1790, p0731

 

I will move this to the 2nd generation Dakota sub-section.

 

sound like the shift sensor is bad