I've been having some issues lately with my truck. Today I was leaving a stop light just applying light gas and the truck got to 20km/h then reved right up and clunked into 2nd gear. Then on my way home I had problems with it kicking back and forth from 3-4 gear while lightly on the gas doing 60kmh. Then I went out to pass someone and I went to step on it and it was dead, no reving no nothing. The truck has about 22,000kms on it and it used to pack a 500lb tidy tank everyday. Its a 06 3500 auto btw. Any ideas and what the problem could be? tranny, torque?