Milky grey gear oil

[Paul o callaghan]

Hi lads I pressure tested my stoke f50 today and found where I think my gear box oil got contaminated. Could someone guild me in the right direction to what part is required? Thanks guys

[TownsendsFJR1300]

Year of engine? Model #?

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[Paul o callaghan]

Shes 2011 f50 4 stroke

[DennisG01]

You'd be looking at, most likely, replacing the seals. But you'll need to inspect the mating surface.

However, I've always heard that pressure tests are practically worthless. The seals, with the way they are placed, are designed to keep water out... but NOT designed to stop oil/pressure from escaping. A vacuum test, I assume, would be a more accurate way to determine integrity.

How much pressure did you use?

[robert graham]

I'd check the drain and vent plug gaskets/washers first, then remove the prop to inspect for fishing line under the seal....might save you the time and expense of prop shaft seals or drive shaft seal replacement...

[99yam40]

I have to agree
How much pressure did you use?
and did you drain the unit before leak checking?
drive shaft and shift shaft seals are showing a problem, but what about the prop shaft seals and orings
and drain screw and vent gaskets

[TownsendsFJR1300]

Per your picture, the top seals, parts #31 (2 of them): https://www.boats.net/catalog/yamaha...casing-drive-1
are leaking/ failed..

I don't see a carrier their riding in, some digging further is needed to R&R them. Inspection of the shaft as well but it's likely ok. With the new seals in, your lower should hold air (at the PSI Yamaha posts for your unit (usually between 10-15 PSI).




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[TownsendsFJR1300]

Spec's for my F150 (FYI):

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[99yam40]

Per your picture, the top seals, parts #31 (2 of them): https://www.boats.net/catalog/yamaha...casing-drive-1
are leaking/ failed..

I don't see a carrier their riding in, some digging further is needed to R&R them. Inspection of the shaft as well but it's likely ok. With the new seals in, your lower should hold air (at the PSI Yamaha posts for your unit (usually between 10-15 PSI).




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looks like #30 is the housing the seals sit in.
looks to me that the shift shaft seal is also leaking.
there also orings that should be replaced on those

[TownsendsFJR1300]

#30 doesn't look very deep but it make sense the seals reside in there... For the Op, might try pulling it.

With all the air bubbles from the main shaft, it's kinda hard to see if there are any other leaks..

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