Water in lower unit oil

Fugley01

Cadet
Joined
Jul 21, 2009
Messages
9
I pulled the lower unit off my 87 70hp yamaha motor this weekend. I've been getting water in the gearcase all summer and have just been changing it. There doesn't appear to be oil getting by the prop shaft. I have noticed oil on top of the shift shaft seal.
When the motor is together can water get in through the shift seal? Should I pressure test first? Any place else I should be looking?

Thanks,

Mike.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
It's either the prop shaft seal, driveshaft seal, shifter shaft seal or one of the washer/seals on the drain/vent plugs....pull prop and inspect seal for damage or fishing line around shaft/under seal.....pressure test would be good if no obvious seals damage...
 

paddlers

Seaman Apprentice
Joined
Oct 1, 2011
Messages
32
Just had similar issues with my 89 V6. Turned out to be the seal under the impeller, fortunately no damage !
 

Fugley01

Cadet
Joined
Jul 21, 2009
Messages
9
I have the prop off and the seal looks good. No damage or signs of leaking oil. There is oil accumulating on the shifter seal. I'll be servicing the water pump so I'll check that seal as well.

Thanks,

Mike.
 
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