mercriser gear lube reservoir inlet hose replum from the side to the top

[sjkuzak]

I was wondering if anyone has ever replummed the gear lube reservoir inlet line from the side of the upper gear case housing vent hole to the very top and center of the upper gear case bearing cover. I have noticed over the years when working on these outdrives some slight staining and pitting on the very top bearing. I was wondering if this is caused by the air pocket that is above the vent hole during winter storage. I was thinking of drilling and tapping the top bearing cover and bringing inlet gear oil hose of the reservoir to the very top of the upper gear case bearing cover. Would appreciate any inputs or thoughts on this subject.

 

[NHGuy]

In use that air pocket disappears. The heat cycle, air, and oil movement eventually allows trapped air out to the bottle. When I run my Gen II it burps in the first few hours and the bottle oil level goes down an inch or two. So I don't know that you gain with a top fill.
Perhaps Mercruiser stayed away from that because of the bearing load on the top plate.
But on the other hand perhaps you are on to something.