Diff problem

[mustangsquared]

I am loosing diff fluid throw threw the relief valve on the top of the right drive shaft....what causes this and is it a PITA to fix? Is there anything else I need to check while I am in there?
Thanks

 

[88stangmangt]

maybe take it out put it back in? maybe try pipe tape when you put it back in? sorry i couldnt be more help.