I have a 99 F250 7.3L 4x4. I had the stub shaft on the pass. front replaced and the hub done also. I engaged the 4X4 about 2 weeks ago for light snow reasons and noted that a few days later there was what appears to be differential fluid leaking out the end of the axle shaft. I have been told that is a sign of a leaking seal in the differential and needs to be changed. I was also told that it may just have been some left over fluid from the previos repair. The repair was back on 9/8/05. Would take any thoughts or advise.