I have a 2001 Dodge Ram Cummins and today I was driving on my lunch break, everything was good so I parked the truck and went to work. When I came out I hopped into the truck and was driving away and the truck would not shift out of first gear. The only way I can get it to shift is by flooring the truck to redline, then letting off the gas. Anyone ever come across this problem?? Thanks

 

Different vehicle, but same symptom - mine ended up as a vacuum line coming unplugged.