Yamaha 90 Drive Shaft Seals

What year are we talking about? Are you able to get your hands on a service manual? It will have the correct procedure to disassemble. It will also have specs to check for serviceability & the correct torque spoecs for reassembly.

‘96. In the research that I’ve been doing, which is mostly washing online videos that housing is always attached with four bolts. Pretty simple disassembly.

There should be pry points(edges that over hang the gear case) on either side of the base of it. It has a sleeve with a couple of o-rings so it’s a bit of a tight fit coming out but it will go. Just work it back and forth carefully with a small pry bar

JustAWrench said:

There should be pry points(edges that over hang the gear case) on either side of the base of it. It has a sleeve with a couple of o-rings so it’s a bit of a tight fit coming out but it will go. Just work it back and forth carefully with a small pry bar

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Ah. OK so it’s just a friction fit? No fasteners at all.

JustAWrench said:

My bad it’s one big fat o-ring not two. View attachment 2865

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thats a huge help, THANK YOU!

milesbarnard said:

Ah. OK so it’s just a friction fit? No fasteners at all.

thats a huge help, THANK YOU!

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No problem happy to help

No that sounds normal. You’re just hearing the forward and reverse gears meshing with the pinion gear on the end of the drive shaft. It will sound a little louder when there is no gear case oil in the lower unit also

JustAWrench said:

No that sounds normal. You’re just hearing the forward and reverse gears meshing with the pinion gear on the end of the drive shaft. It will sound a little louder when there is no gear case oil in the lower unit also

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10-4 Thanks again

No problem!

It’s easier to change the seal with it out. It’s held in there the same way as the water pump housing base was (on an oring) just be careful removing this one as it’s plastic (obviously). You can use a small pick and pry the old seal out but care must be taken when installing the new one over the shift shaft if you go this route. Once you get all seals replaced a pressure test should be done on the lower unit to confirm all seals are holding correctly.

Okay that all makes sense. I might try using something like a putty knife to break the seal under the housing to work it up and out. I assume I could break the plastic if I try prying it out like I did the water pump housing base.