I am wondering about the bolt holes in the top of the axle housing that the platform bolts to. The holes are not blind holes and seem to have a cavity under them. I thought these just dropped into the main cavity where the main driven axle gears are put apparently they do not. I tried pouring some kerosene in one with a funnel to clean out any material that may be there and it bubbled back as the air was trying to get out, so it seems they are sealed. Anyone had the axle housing apart enough to shed some light on my question?