My 2011 Ram will shift out of D to 1st or some lower gear by itself, then eventually may shift back to 3rd, 4th or 5th by itself. at 60 mph seems dangerous to me. sends rpm skyhigh. Also when i start to leave it will not shift to D and stay, it just shifts down to 1st or 2nd. Anyone had this problem and any ideas? does not do it all the time. I have 148,000 miles on it.