Over the last two oil changes I have noticed the outside of the filter has a light film of oil on it at change time. The same light film can be found on the front axle and steering components. I put 5qts in at change time, I recover 4.2qts plus whatever's still in the old filter. The filter isn't loose, I make sure it's good and tight. Is it possible it's just road grime from 3K miles of driving? Or am I deluding myself to avoid a repair bill?