it could be that your seals are just old or that they were damaged when the axle was reinstalled. mine was leaking pretty bad so when i changed my clutch i also got new axle seals. it doesn't leak anymore
dsm/mitsubishi service manuals https://www.mediafire.com/folder/5k14qlaulb9s1/dsm_mitsubishiservice manuals(my whole collection) https://www.mediafire.com/folder/ac51jwwa3g1n1/automotive_manuals