2003 Freightliner Columbia Oil Leak.

So i just recently bought a truck and i finally found out where the oil leak is from. But question is what needs to really be done to it?

Truck has 1.4 Million km's on it 800+k Miles i circled where the oil is coming from no other leaks can be found and engine oil is not seeing any coolant as i did oil change..

Thanks for any advice

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2003 Freightliner Columbia Oil Leak.