A few years ago we started design/engineering on a new housing that is a little larger, much stronger, and more precise than the original castings from overseas. Although there is no possible way to keep a faulty primary design from forcing oil into the starter completely, we have made all possible changes to the starter housing to minimize the issue.
We may be criticized and questioned for the lack of the "oil groove" cut in these. As far as we are concerned that was post production "band-aid" by Big Dog that didn't fix the problem of oil entering the starter. It serves no purpose other than creating another avenue for oil to enter the starter. Once oil enters the starter it doesn't come out. Damage is already done because oil shouldn't be in the starter in the first place.
Let's check out the video walk-thru