Gear oil leak, but from where?

Drcoffee

Petty Officer 1st Class
Joined
Aug 26, 2021
Messages
220
I have had the boat for 3 years, 1995 Rinker 212 captiva, mercruiser alpha 1 gen 2. The first winter I replaced the sea water pump and everything went well, no problems. Last winter I removed the out drive and stored it in my garage. Bought new quick silver gasket set and reinstalled it this Spring. Seemed to go together correctly after following Chris’ video. Torqued it to spec. Took it out for the 4th time this year and when I lowered the out drive down in my driveway before heading out, gear oil drained out of the raw water intake on the lower unit, where muffs get installed. Id say less than an ounce. I checked the oil level at the top screw and clear oil drained out. The reservoir was down about 1/2” from the line. What did I miss when I reinstalled the outdrive? Where would this oil be coming from? Should I be concerned water is getting in The baffle of the driveshaft? The gear oil connection should be sealed with the gasket. Should I have coated the gasket with permatex aviation paste?
 

IanFS

Petty Officer 2nd Class
Joined
Apr 21, 2009
Messages
188
I have had the boat for 3 years, 1995 Rinker 212 captiva, mercruiser alpha 1 gen 2. The first winter I replaced the sea water pump and everything went well, no problems. Last winter I removed the out drive and stored it in my garage. Bought new quick silver gasket set and reinstalled it this Spring. Seemed to go together correctly after following Chris’ video. Torqued it to spec. Took it out for the 4th time this year and when I lowered the out drive down in my driveway before heading out, gear oil drained out of the raw water intake on the lower unit, where muffs get installed. Id say less than an ounce. I checked the oil level at the top screw and clear oil drained out. The reservoir was down about 1/2” from the line. What did I miss when I reinstalled the outdrive? Where would this oil be coming from? Should I be concerned water is getting in The baffle of the driveshaft? The gear oil connection should be sealed with the gasket. Should I have coated the gasket with permatex aviation paste?
I've got a similar problem but with an oil dribble in the prop, the guys on here have been so helpful.
However in your case if its coming out of the water intake, it could be the water pump seal leaking but thats been replaced or it could be the upper drive shift seal leaking and dribbling down the drive shaft round the pump and into the intake.
In my case the main suggestion was to pressure test to 10lbs psi and see if it holds.
 

Drcoffee

Petty Officer 1st Class
Joined
Aug 26, 2021
Messages
220
Thats a good thought. When I did the pump I did not replace the seal below the pump. Thats probably be where its coming from. Any other place would come out the exhaust or prop area
 

mvn

Petty Officer 1st Class
Joined
Jul 25, 2007
Messages
204
Also check the shift shaft and shift shaft seal. If the shift shaft was not in the proper position when reassembling, the shaft may have been tweaked causing a leak.

Mark
 

Drcoffee

Petty Officer 1st Class
Joined
Aug 26, 2021
Messages
220
Also check the shift shaft and shift shaft seal. If the shift shaft was not in the proper position when reassembling, the shaft may have been tweaked causing a leak.

Mark
*I forgot to mention, the boat was parked on the trailer for 3 weeks so its a slow leak.
I dont think the shift shaft has access to below the pump. Any leak there would not drain to the water inlet. BTW I changed the shift shaft seal and speedo connection too with the pump service.
 
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stresspoint

Lieutenant Junior Grade
Joined
Sep 19, 2022
Messages
1,045
i mean the check valve for the gear oil reservoir.it has a rubber seal.
also i don't trust quicksilver gaskets , although they pass them as being OEM , yea right !
 
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IanFS

Petty Officer 2nd Class
Joined
Apr 21, 2009
Messages
188
Thats a good thought. When I did the pump I did not replace the seal below the pump. Thats probably be where its coming from. Any other place would come out the exhaust or prop area
Mine, Alpha One, has another housing onto which the impeller housing sits, whereas a Gen 2 the seal is the cone below the impeller housing, usually yellow. Sounds as if that's the problem if not replaced 🤔 Let's hope that's the culprit eh?
 
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