Hello again with my dumb questions as I'm a new owner operator with my first truck I'm trying to get up and running. 04 freightliner with a Cat C12 oil pan has oil and grime caked on all over it. Would this be as simple as me replacing the oil pan gasket? I don't see any oil leaks above it coming from the engine as far as I can tell. Noticed all this while I was underneath changing the oil today.