Check out the pics. 99 f250 4x4. I have a leak in my front axle shaft. It looks like it is coming out of the dust cap on the end of the front shaft. I am pretty sure it is differential fluid from the smell. Is there a seal before the dust cap? Is the shaft hollow with fluid in it? I thought it was just in the differential and if it leaks it is at the seals where the axle goes into the differential not at the otter end. Thanks for the help

 

There is a inner seal close to the pumkin on both axle tubes. If you have fluid coming out the end then that inner seal is bad. The tubes are not suppose to have any fluid in them..

 

Pics added.