2004 F115 Water in Lower Unit

[Junior]

I posted last fall about water in my gear oil. This spring before un-winterizing, I drained the new oil out and pressure tested. No leak down. This fall, water again. Any other way water can get in the unit?

[robert graham]

Water can leak in the gearcase through the drain/fill plug washers/gaskets, the prop shaft seals, the drive shaft seal or the shifter shaft seal. Check first the drain/fill plug washers, then remove the prop and inspect for fishing line around prop shaft and under that seal, causing leak and/or damage to that seal. Then you can drop the lower unit and inspect the driveshaft and shifter shaft seals. Good Luck!

[Junior]

I've checked all of that. I thought the plugs may have been loose last year. Always change gaskets, etc. No visible leaks or line around prop shaft. Had water pump done last year. After that is when I found the water. Unit is at a mechanic now.
He called me and said water was coming from somewhere else???? Something about oil pump seals? Doesn't sound like it is even remotely the same issue. Could they diagnose something with the seals in the powerhead from looking at the shaft?
Wondering if the dude is BS'ing me.

[Inducted]

If you drop the lower unit and found engine oil on the drive shaft then you could assume the oil seals in the pwer head MAY be leaking oil, But this would not put water in your LU. Maybe he meant the oil seals for the drive shaft in the lower unit are leaking. Proper pressure test of LU should find the leak, sometimes you have to push,pull or turn the shaft to find the leaking seal. Hope your not getting ripped off!

[Junior]

I hope I'm not getting ripped off either. That's why I'm inquiring. I didn't look closely at the top end of the drive shaft. It obviously had grease (which is good). The rest of the shaft wasn't coated with oil. It was rusty.

[Junior]

Outcome being resolved

Last week after unwrapping the boat, brought it to the mechanic. Turns out oil seals are bad (scored the shaft). Didn't know to look for that when I removed the unit. Power head is coming off for oil pump assembly replacement. The shaft needs to be replaced as well do to the damage. He felt there may have been a wobble in the shaft also which led to the water intrusion. ??? He mentioned another bearing in the lower unit they were going to inspect. He mentioned Yamaha now deems this bearing a wearable item????