1990 Suzuki DT8CLL oil leak.

Sundodger

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Jul 11, 2011
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When I pulled my boat out of the water yesterday from a bit of fishing I saw some milky oily fluid leaking out of this bolt (see red circle in picture below).

I drained the lower unit oil and that looked clean. Other than the oil for the engine, I can?t think of where else there would be oil that could get contaminated and leak.

Anyone have any ideas?

 

tommarvin

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Nov 22, 2015
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999
I guess your driveshaft seal is leaking, and its draining out through that bolt. I'm assuming that is one of the bolts that holds the lower unit on.
If so drop LU remove water pump housing to get to the seal.

Free factory service manuals at www boatinfo.no/lib/library.html Check iboats.com first, to see if they have the seal.

Or is this the fill plug that was lose and leaking gear oil.#7and #8
 

99yam40

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my guess is if it does not smell like lower unit lube then it has to be 2 stroke oil
 

flyingscott

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typical 2 strk sounds like unburned fuel coming out bolt might be loose.
 

Sundodger

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Jul 11, 2011
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Thanks guys.

Yeah it is coming out of one of the bolts that holds the lower unit on.

I am going to take a closer look (and sniff tonight). I should have time to pull the lower unit off if I need to inspect the driveshaft seal.

If you have any other ideas I would love to hear them, either way I will let you guys know what I find.
 

tommarvin

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Nov 22, 2015
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You can do a five pound air pressure test through the fill hole, I think you have to drain the gear lube to do it. Iboat.com may have the adaptor tool
Torque the LU bolts to spec, HF has a inch pound torque wrench for 12 bucks, start a good habit now.
 
Last edited:

Sundodger

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Jul 11, 2011
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Turns out a gasket below the waterpump had failed. New gasket and everything passed the pressure test so I am good to go!

Thanks guys.
 

Sundodger

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Jul 11, 2011
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Well it's back again...

I have taken the boat out a few times since the repair, and this weekend when I pulled it out I saw this. I talked to the repair facility that replaced the gasket last time and they didn't think this was a problem at all and was typical. Maybe that is true, but I guess I am having a hard time believing it because I/my father has owned this engine since new (1990) and we haven't seen this before...

Any ideas or recommendations on where to go from here?

 

99yam40

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You never came back and told us if it smelled like lower unit oil or something else
 

Sundodger

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Jul 11, 2011
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You never came back and told us if it smelled like lower unit oil or something else

Thanks for reminding me.

The lower unit oil looked and smelled great, no burnt smell or milkshake from water intrusion.

I haven't checked it this second time though...
 

99yam40

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what I was getting at was, lower unit lube stinks/smells a lot different than 2 stroke oil or 4 stroke motor oil.
I was trying to make sure what kind of oil was showing up on the leak.
Does it smell like lower unit lube or not?
 

tommarvin

Ensign
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Nov 22, 2015
Messages
999
Better drop the lower unit, takes 5 min and take a look with your own two eyes.
Is it the seal on the driveshaft ?
 
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