What seals the lower unit to the rest of the motor?

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: What seals the lower unit to the rest of the motor?

There is no seal. Exhaust and warm water from the powerhead go down the inside of the midsection all the time. The lower unit itself has seals that keep oil in and water out. They are usually located just beneath the water pump on the drive shaft, and on the prop shaft right behind the prop, as well as on the shift shaft. Drive shafts and such are stainless steel in most cases now to prevent corrosion. That's why there are usually a couple of tiny holes just beneath where the lower unit joins the midsection-----so water can drain out of the midsection and not freeze inside there, breaking stuff.
Later,
JBJ
 

MassillonBuckeye

Chief Petty Officer
Joined
Jul 26, 2010
Messages
400
Re: What seals the lower unit to the rest of the motor?

There is no seal. Exhaust and warm water from the powerhead go down the inside of the midsection all the time. The lower unit itself has seals that keep oil in and water out. They are usually located just beneath the water pump on the drive shaft, and on the prop shaft right behind the prop, as well as on the shift shaft. Drive shafts and such are stainless steel in most cases now to prevent corrosion. That's why there are usually a couple of tiny holes just beneath where the lower unit joins the midsection-----so water can drain out of the midsection and not freeze inside there, breaking stuff.
Later,
JBJ
Thanks for the reply. So basically some water getting in there isn't the end of the world.
 

Triton II

Commander
Joined
Nov 23, 2004
Messages
2,479
Re: What seals the lower unit to the rest of the motor?

Thanks for the reply. So basically some water getting in there isn't the end of the world.

No, it's not a problem, the water will drain unless the drain holes are blocked. Have a good look next time you run the OB on muffs and you'll see water draining from all over the lower leg.

TII
 
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