I have a 1986 Alpha 1 Gen 1 mercruiser outdrive. There is a small oil leak that seems to be coming from the shift shaft. I was told that the bottom does not have a seal, just a bushing. The top of the shaft is supposed to have two seals. Is this a known place for these units to leak oil or could there be another reason. Is there oil above these seals and where would this oil come from. It seems that i also have a small amount of water in the gear oil when i drained it. If i change the upper shaft seals would this solve my problems? Thanks for any help. Your help would be greatly appreciated.