Gear lube leak somewhere

badrano

Petty Officer 1st Class
Joined
Aug 7, 2018
Messages
381
I've dug through the various posts about gear lube leaks but can't seem to determine what my issue is from those posts.

I bought the boat last year and got a few runs with it before winterization. I had a feeling I had leak somewhere because I had to top of the lube oil monitor. When I winterized the boat, I pulled the stern drive out and the drive bellows was clean so I thought there was no issue with the bell housing gaskets/o-rings. So far this season, I've topped the lube oil twice.

After reading the various posts, I don't see any drippings on the ground. I don't see anything on the engine side of the transom either.

I've read that in some cases the seal/o-ring around the prop shaft may need to replaced. Would a bad seal allow oil to drip to the ground when parked on the driveway? Looking at the parts blow up diagram, which seal is it?
 

badrano

Petty Officer 1st Class
Joined
Aug 7, 2018
Messages
381
remove and split the drive, remove the water pump housing and SS base plate, plug oil transfer hole with something, golf T, pencil point, etc pressure test.More than likely its the shaft seal under the water pump housing
3B-6 #18 in here http://www.boatfix.com/merc/Servmanl/14/14b3.pdf

Hmmm....would that mean the oil would leak in to the cooling loop? I ask because I noticed a couple times when running the engine off the muffs in the street, I could see an oily film on the water running down the street. At first I thought this may be coming from the exhaust mixing in with the water discharge.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Hi

every year I change my gear oil and allow the header tank to drain too. Quick clean of any sludge in bottom if tank required first time usually.
After refilling the drive the usual way then topping up the header tank.....there is always a void of gear oil between the header tank and the drive. It naturally drains the header tank as it settles to level. Couple of top ups the first few times out and it’s good.
 
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