Ow me shafts!

[oldmako69]

F4D8832F-3F85-444F-9C8C-3CF7C5997EC7.jpeg


2014 F300s. Approx 900 hours. New to me last fall.


Both of my shafts are scored like this. I'm guessing that sand has gotten into the seal at the base of the engine's leg. I'm also guessing that the seals just pull out and that new seals can simply be tapped in.

Any advice besides new seals and grease?

[99yam40]

I would think new shafts and other stuff is needed

[oldmako69]

I'm disinclined to replace the shafts unless it's absolutely necessary. They're $600 each and then I'd probably have to pay a tech 2-3 hours each to remove and replace them. So I'm looking at least 1500 bucks for what? I ran the boat about 50 hours last fall and the engines performed flawlessly. Hard to imagine that a score there is that big of a deal. Unless you educate me on something that I don't know.

[99yam40]

all of the shafts I have seen had seal surfaces that were the same diameter as the areas around them, but I never laid my eyes on a ones from 300s.
but hard to me to think those seals would do their job on that shaft.
just getting the seal/shaft to that sealing surface may damage the seal

let us know how this works out, I am interested

[oldmako69]

I don't believe that it's a seal. It's a driveshaft bushing. Looks like hard plastic of some sort.

https://www.boats.net/product/yamaha...1cc4c443d97fb0

I think it's there to stiffen any wobble out of the shaft just an inch above the water pump.

[TownsendsFJR1300]

Part #32 is a bushing (per pic's), and above the WP are two seals and a retainer (parts 15 and 20), (which I don't see on your LU). Is the c-clip and bushing (32 and 33)
still in the mid-section?

On my F150, there is a mid section bushing also held in with a clip but that bushing is fairly tight and does NOT turn in the
mid section. That bushing requires greasing (between the shaft and bushing) so it doesn't seize up.

Kinda looks like your bushing is now attached to the shaft and NOT the mid section...




https://www.boats.net/catalog/yamaha...







Capture 2.JPG

[oldmako69]

The bushing is still in the midsection. I'm going to remove it and clean it up. Replace it if needed. I'll put WP grease all over the shafts and reinstall. Then cross my fingers and check them in 100 hours.

[TownsendsFJR1300]

Make sure you use the waterproof Yamaha stuff or equivalent grease.

Regular "marine grease" won't hold up where that bushing rides (it'll wash out / squeak, etc)


Are parts #15 and 20 there?

.

[oldmako69]

Understand fully on the grease. "Page not found" on your link so unsure what 15 and 20 are.

[TownsendsFJR1300]

Understand fully on the grease. "Page not found" on your link so unsure what 15 and 20 are.

https://www.boats.net/catalog/yamaha...casing-drive-1

Parts 15 and 20, 15 are two seals, part #20 is a "Cover, water pump housing".



Sorry bout the first bad link, apparently my boo..

[oldmako69]

I think 15 and 20 will be included in the water pump kit, but I am not sure. Once I tear into it I'll know. Today I just popped the water pumps off. No idea when they were last done, but the impellers appear as new and all of the bolts holding them and the shift plate cover were all covered with fresh reasonably fresh grease with no corrosion.

I bought it with about 860 on the engines and was told they'd need to be done at 900. So, I'm right there. Very pleased to see the drive shaft seal/covers (part 64) appear to be in excellent condition. On my 225s they were horrid and clearly had been leaking.

[zenoahphobic]

Always makes you cringe what you find when pulling apart outboards.