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Alpha One, gen 2 water leak

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2000186

New member
I have a mercruiser alpha one gen 2 sterndrive. I am getting water in the gear oil. I get water faster when cruising verse when doing more swimming. I have installed new gaskets. I have separated the lower from the gimbal housing. When I pressure check the stern drive, it holds pressure. When I pressure check from the reservoir to the gimbal housing, it also holds pressure. When I put the two back together and pressure check, it loses pressure in that connect for the stern drive to the gimbal housing.
 
What pressure are you testing at?
I test all at 15 psi.

Also when under pressure turn by hand one at a time, prop shaft, ujoint shaft, verticle drive shaft (lower unit) and shift shaft.

If you can get a vacuum tester that would be next, should pull ~ 6-8 inches if i remember correctly
 
kghost said:
What pressure are you testing at?
I test all at 15 psi.

Also when under pressure turn by hand one at a time, prop shaft, ujoint shaft, verticle drive shaft (lower unit) and shift shaft.

If you can get a vacuum tester that would be next, should pull ~ 6-8 inches if i remember correctly
Click to expand...
Thank you! I think I was putting 20lbs on it. I can try vacuum next. I will try moving everything next.
 
20 psi is to high.

A drive will produce ~ 7-9 psi.
15 is more than enough.

Merc actually doesnt have a spec.
OMC had one, 17 psi.
So i use that as a start but went to 15 psi and that will work 99.9% of the time.
 
Alright, I pulled the stern drive. Found that the shift shaft seal is leaking terrible, so I will rebuild that. Another problem is that there was a lot of water in the bellow that surrounds the ujoints and to the gimbal bearing. Any ideas there?
 
Shift shaft bushing assembly (seal and body) should be replaced. Sold as an assembly.
Needs a special tool to remove and properly torque new one.

Water in bellows, many possibilities.

No idea what your year boat is, conditions its used, stored in...what is the maintanence history...etc etc.

You can get 10 different reasons with no one knowing any of the above.

If you do not have a service manual you really should get one.
 
It’s a 2000. I bought it a couple years ago not knowing what to look for. So I got something that obviously needs some work. No records. I replaced all the bellows last year. There shouldn’t be any cuts or cracks in those bellows. I am far from calling myself a boat mechanic so I am learning as I go. I am an ag mechanic so I’m not totally green.
 
kghost said:
Shift shaft bushing assembly (seal and body) should be replaced. Sold as an assembly.
Needs a special tool to remove and properly torque new one.

Water in bellows, many possibilities.

No idea what your year boat is, conditions its used, stored in...what is the maintanence history...etc etc.

You can get 10 different reasons with no one knowing any of the above.

If you do not have a service manual you really should get one.
Click to expand...
Thank you the knowledge. I was thinking there was a specific tool involved in that part.
 
Here is the tool, cheapest may be best so shop around. You may only use it once.
 

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2000186 said:
Thank you the knowledge. I was thinking there was a specific tool involved in that part.
Click to expand...
Gen two does not require tool shift shaft seal is in the assembly attched.

just did mine as part of a complete reseal. All seals were ok except the shift shaft seal which was dried out. get Your bellows replaced if there is water in there only will ruin gimbal bearing, inout shaft seal and u joints
 

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If not the bellows, another way water can get in there is if water has collected in the bilge enough to run back through the driveshaft. Remember when pulling up a ramp it might not take that much.
 
Mark S. said:
If not the bellows, another way water can get in there is if water has collected in the bilge enough to run back through the driveshaft. Remember when pulling up a ramp it might not take that much.
Click to expand...
that makes sense. there is a ramp at i use that is very steep. could be a possibility.
 
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