Ford dealer replace pass front axle seal (4x4) where half shaft goes into diff housing 1 year ago due to oil leaking out. It is now wet again and the put dte in and said is oil from the new seal design and not diff fluid. Anyone know of TSB's or any info on this. I would also get an ocassional bang with seemed to come from front end when turning and in 4x4 on total snow covered roads, no dry pavement. My tires are less than 1 year old 8,000 miles and the say the diameters are 1 " of causing this, I asked if they checked pressure of tires and they said no. All advice appreciated.