I just purchased a 98 1500 5.9L V8 SFI OHV 16V two days ago. I test drove it several times and everything was fine. I paid for it and headed for home. I purchased it from a private owner about 80 miles from me. It ran like a dream all the way home till I got off the interstate then the transmission started slipping. I made it home and checked all the fluids again and all are showing full. I went to test it again after letting it cool down and now it wount shift out of first. I am hoping I didnt get taken here. I would appreciate any dvice about where to start.

 

Typical Dodge tranny. Go have it looked at...

 

Try changing the speed sensor on the tail shaft of the transmission.