potential oil leak

[pooleo]

When I had my trans out doing my clutch, I looked into the oil that has been leaking on my truck. From previous oil changes it seemed as tho the filter was not tight enough. Filter was usually wet with oil as if it were leaking from the o-ring. I also thought possibly rear main. I replaced the rear main when the trans was out. inspected the oil pan gasket and all seemed well, dry, and clean. BTW, the rear main was NOT leaking.

I guess I'm not entirely sure of the oil filter housing on how its mounted. Is this something that is bolted to the block? Could it be leaking from a mounting location? Filters are tight and the O-ring from previous filters is not sticking to it. Had that happen before, plenty aware of that!

Any thoughts would be appreciated.

Places I KNOW its not leaking from:

Rear main.

Oil pan/gasket.

Valve covers.

Front main seal/timing cover area.

Oil filter.