Prop Shaft Leak

[Skins88]

So, I had the garage door open for a few hours yesterday and my merc 9.9 was sitting in direct sunlight. Was about to close the door and call it a night when I noticed gear oil leaking out of the prop shaft. Guessing the heat caused this. I talked to Haney Marine. They said it could be fine or pooched. Any of you guys ever experience this?

 

[daddystoy]

Well I will throw a reply at you. I'm no marine mechanic but consider myself somewhat mechanically inclined and I would think that heat from the sun is not going to cause a leak on a prop shaft.
You need to do a pressure test and a vacuum test on the lower gear case to diagnose what is going on.

 

[SpringVelocity]

Prop shaft seal. That would be my guess. Check your gear oil.

 

[pescador]

Pressure test it. Best means of determining a faulty seal.

 

[profisher]

It can be the seal but can also be the prop shaft..a slight bend will cause the seal to leak as will a groove worn into the shaft by the seal riding on the same spot every hour the engine runs...more hours on the engine the more likely that can happen. If it is the prop shaft they are usually still available from the dealers.

 

[Skins88]

I will probably take it in. Next time I use it will be over in Bamfield. Not the time to find out there is a real problem. Just weird that it would start leaking out of the blue while it's sitting on the bench. Hadn't been in the water for months.

 

[profisher]

Pressure test it. Best means of determining a faulty seal.

I've had water in my Yami 9.9 and the pressure test held so we refilled with new gear oil and ran it for the summer. After summer and checking the oil, water in it again. Turned out to be a very slight tweak of the prop shaft that you couldn't see by spinning the prop. It only leaked when the prop shaft was tuning as the motor was being used.