Re: lower unit gear oil leak! 90 Evinrude
In freezing weather, if water was within a lower unit in any quanity, the water would do more than simply push a seal out.... it would actually cause the lower unit housing to crack which would usually be quite visible.<br /><br />Are you sure that what you are seeing is actually gearlube, or might it actually be the gasoline/oil mixture running down the inner portion of the long exhaust housing between the powerhead and lower unit, then oozing out the carrier housing (propshaft housing) and the small water drain/outlet hole that you mention.<br /><br />Remove the lower drain plug screw from the lower unit and compare the lube with what you're speaking of. If the coloring etc is the same, in all likelyhood you have a lower unit seal leaking.<br /><br />If on the other hand, the gearlube looks normal but what you see leaking is pure black, chances are that the lower unit is fine.<br /><br />Water in the lower unit will appear in two different ways.... either the lube will appear milky, or pure water will be present and will run out as soon as you remove that lower drain screw.<br /><br />If any uncertainty exists, drain the lower unit completely, then replace just one screw, either the lower drain screw or the upper lube level screw, it doesn't matter. Then, apply 7 to 12 pounds of pressurized air to the open screw hole. That pressure will reveal any leakage of the lower unit seals etc by sight and/or sound.
