So. 2 nights ago truck made a whirring sound while driving and then stopped moving forward. I was able to pull over and found that I had a drive and reverse..... was also able to put the shifter through the Gears normally.....in D , I take my foot off the brake and it pulls forward like normal .... there’s just no acceleration. Engine revs ..... truck creeps. No issue with reverse ( I didn’t try to go at any speed ..... it was towed to a garage ..... filter and gasket were changed ..... no pieces of carnage of the transmission in the pan. They put 4 gallons of fluid in and no change......it’s now at the tranny shop and of course they are shutting down for the long weekend. He mentioned a wire or harness that can corrode ??? Esp in this particular generation of f series..... just wondering if there was any insight available...... I love this truck and am always trying to learn more about it. It’s a beast!!!!!