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HELP - Water in Lower Unit (1999 70hp 4-Stroke)

C

ctmsnow32

New member
Hey guys I checked my gear lube recently and found it to thoroughly milky. I drained everything and had it pressure/vacuum tested. Everything passed with flying colors. I then checked the prop shaft and its straight.

Does anyone have suggestions as to where I could be getting water in at?


Thanks
 
Did you check the oil 5 minutes after it ran or 3 days after it ran ?-----Did you put the oil in a glass jar to see if water showed up at the bottom ?
 
NOTE that when pressure testing... Do Not exceed 7 to 12 psi as any greater pressure would have the effect of slamming a failing seal shut.

When the engine is running, if any driveshaft, propshaft, or shift rod play exists due to a warn bearing etc... the shaft will sway sideways (sometimes) to a greater degree then the seal can tolerate.

Rule of thumb when in doubt as to the leakage location... replace them all, everything. It's cheaper then replacing the lower unit!
 
Thanks for the insight Joe. Just to clarify you are suggestions to release the bearings not the seals correct? I was also told its possible, that while driving, the motor could be vibrating enough (prop damage or skeg damage) to cause a leak and this would happen without me feeling the vibration.

Which is the more likely issue? The bearings or prop/skeg?
 
In 30+ years at the bench, I never heard of the vibration/leakage theory.

My vote goes for the worn bearing... BUT... at the low pressures I indicated, the leakage area should show up.
 
joereeves said:
In 30+ years at the bench, I never heard of the vibration/leakage theory.

My vote goes for the worn bearing... BUT... at the low pressures I indicated, the leakage area should show up.
Click to expand...


Yea maybe the shop I brought into was no good? They said it held 15 psi for 6 hours...
 
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