My front axle is leaking the gear oil?

i took my truck mudding %26amp; on my way home i noticed a smell so i checked %26amp; opened the hood %26amp; seen the breather line that comes from the front axle letting oil out it was brown oil i first thought it was mud water. Then i looked at the axle %26amp; saw that it was leaking out of the driver side. Its the stock axle (GM 10 bolt) is it just a seal/gasket or a bearing. I noticed it was vibrating for a little bit before i noticed the smell but i thought it was the spare i threw on. It doesn't vibe anymore %26amp; i still have that spare on. I took the plug out of the front diff cover %26amp; checked the oil level %26amp; it's almost completely empty.My front axle is leaking the gear oil?
Your axle seal.


Within the past year I have had the driver's side and passenger side axle seals replaced on my truck. They were both leaking. My front axle is leaking the gear oil?
replace the axle seal and fill it back up
bad axel seal