I brought my truck in to get the clunk fixed. They looked and my drive shaft wasn't clunking. They DID notice that ford has sent out a computer update for the 5.4 transmission. It supposedly changed the way the clutch acts, and shift mapping up and down through the gears. I got but had to immediately go to work which was right around the corner, so no test drive. Later that night heading home I got to see the difference. HOLY GOD! Its so much better now. There is no gear hunting, regular driving shifts are firmer, but much smoother. I did a 0-75 pull and DAMN! It sets you back in the seat pretty hard now. I jumped on the highway and the dreaded lag time when passing is no longer. Throttle is immediate and shifts to the CORRECT gear the first time. Everyone with a 5.4, get your truck to the dealer!