1991 Mercruiser Alpha 1 Gen 2 Leak

Roadblock007

Petty Officer 2nd Class
Joined
May 24, 2017
Messages
142
I've had the boat out of the water for about 3 weeks now and noticed a small drip under the outdrive. When I looked closer it is the green outdrive fluid coming from the seam between the upper and lower unit right at the front. I wiped it down to make sure it isn't coming from anywhere else. It is just leaking, very slowly, from that seem. I had one of the tilt cylinders rebuilt and a full tune up and outdrive oil change including the lower unit about 2 months ago. Right after that I ran the engine every day on the lake for about a week. The fluid is a nice deep green and has just started in the last 2 weeks and is very slow. Approx. a tbsp. in the last 2 weeks.I leave the drive tilted up while in my driveway and have checked the bolts and they are not lose. Any suggestions?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,346
shift shaft seal, shift shaft housing, lower drive shaft seal under the water pump cover
 

Roadblock007

Petty Officer 2nd Class
Joined
May 24, 2017
Messages
142
Thank you.

Is there a risk of water coming in and mixing with the oil and causing damage if I use the boat before I replace these seals? I wanted to use the boat a few more times this season before pulling the outdrive and doing water pump, bellows, and checking gimbal bearings and seals.
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,775
It is possible to get water in, when you said it was deep green fluid was this out of the leak or out of the drain screw? If you didn't check the drain screw open it and see if the oil is milky. If not you're probably ok to use it for the last few weeks of the season. Just watch the lube bottle for low (oil going out) or high level (water coming in). I think the HP gear lube can tolerate some water intrusion and still be ok, but just make sure to drain it when you pull the boat in case water is in there as it can freeze and crack.
 

Roadblock007

Petty Officer 2nd Class
Joined
May 24, 2017
Messages
142
It is possible to get water in, when you said it was deep green fluid was this out of the leak or out of the drain screw? If you didn't check the drain screw open it and see if the oil is milky. If not you're probably ok to use it for the last few weeks of the season. Just watch the lube bottle for low (oil going out) or high level (water coming in). I think the HP gear lube can tolerate some water intrusion and still be ok, but just make sure to drain it when you pull the boat in case water is in there as it can freeze and crack.


Out of the leak. I didn't check the drain screw.
 
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