'57 Fastwin 18 hp Water in Gear Case

[DaBrickster]

Finding water in my gear case. I know its not coming from the gear housing because no oil is leaking out. I have a feeling its coming from the lower unit. What stops the water from entering the gear case from the lower unit? Is it the bushing around the drive shaft? I also see an o-ring that sits just above the impeller housing and can't quite figure out how that functions on the shaft. Any help would be appreciated.

 

[Fuzzytbay]

Re: '57 Fastwin 18 hp Water in Gear Case

it could be the gear case leaking around the seam. Water is thiner than oil, and when the motor is running the water is also under pressure, pushing into that joint. It could also be the shaft seal, too.

 

[DaBrickster]

Re: '57 Fastwin 18 hp Water in Gear Case

I see your point. I am going to try to replace the shaft seal and seal the gear case housing . Thanks for the reply.

 

[1946Zephyr]

Re: '57 Fastwin 18 hp Water in Gear Case

I would just belly up to a reseal kit, that way you won't have to tear into it again. I have a 57 Fastwin with the same issue too. Welcome to the crowd.

 

[DaBrickster]

Re: '57 Fastwin 18 hp Water in Gear Case

Any idea of the sierra part number?