Water in lower unit oil - Merc 9.8

[festx]

I went to change the lower unit oil today in my Merc 9.8 (6517178) before I took the boat out for the first time this year. When the oil was draining I realized that there was water in the oil. After I disassembled the lower unit I noticed that there are 2 hairline fractures on the upper part of shift shaft bushing next to the oil seal. Can I safely assume that these fractures are leading to water getting into the lower unit oil?<br />Also, what could cause these fractures? <br /><br />Thanks in advance.<br /><br />Steve

 

[Bob H.]

Re: Water in lower unit oil - Merc 9.8

Not familiar with that particular engine but if the shift seal is over the bushing and not on either end it's possible that water got in. Better bet is the water pump seals.

 

[Laddies]

Re: Water in lower unit oil - Merc 9.8

If the shift shaft bushing is cracked it would leak, but the most common leak in that series of engine is the drive shaft seals, the shafts pit quickly--Bob

 

[festx]

Re: Water in lower unit oil - Merc 9.8

I replaced the shift shaft bushing and seal and the seal under the water pump. When I had the lower disassembled I replaced the impeller as well. I reassembled the motor and now it is not pumping water ( at least not through the pis hole). What could it be? I replace the impeller every year and never had this problem. Thanks.<br /><br />Steve