This morning went out and truck seems to stay in OD at low speed. It will buck and stall before coming to a stop. If I pull the shift lever down to D1 or 2 it seems to shift OK. At speeds above 40 or so it seems normal also. Can't drive it like this , could this be the TPS that I've read about here?
What could happen so quick , had no warning of a problem? Need some help , thanks.

 

Do a search on the TPS. There are tons of articles on it...