My 2002 f350 crew cab automatic.When it has been parked for a couple hours (mostley notice with a load on truck )It will not move.Can have the throttle pegged but rpm not going up all the way.Could not tell you exact rpm.It will not spin a wheel. The most resent issue was i was pulling wave runners out of the lake.Was just on the shore.I had it in four low first gear and four wheel drive.I had to have help push me out.never spun a tire.Truck was sitting just before i backed into water to get wave runners, but it was 95 plus degrees that day.Ford says they cant find anything. any ideas.