First time I've ever had this issue in my 2007 Ram 1500. I was driving at 60mph today and out of no where I get this clunk type noise and my truck downshifts into 4th gear. Pulled over, turned it off, restarted and drove away. No issues at all. Drove the rest of the day without issue, even with cruise control on. Fluid is about 6-7 months old and at the correct level. No codes pulled with my programmer. Time for a rebuild? Solenoid?