Alpha 1 gear lube leak

[SDSeville]

Just changed the impeller and oil seal about 2 months ago. I have run it about 6 hours with no leaks. It sprung a leak just sitting in the driveway yesterday (hasn't been started in a few weeks). It is leaking out the weep/drain hole on the starboard side.

I will be taking it apart this week, but wanted to see what you guys think. I am guessing the shift shaft seal. Anywhere else to look?

 

[thumpar]

Before you take it apart pressurize it.

 

[SDSeville]

Thanks -- will make or buy the tester tonight. Do you ever see a leaking drive hold pressure?

 

[FreeBeeTony]

You need to drain it before you pressurize it........

 

[achris]

Have a read of this -> http://forums.iboats.com/mercruiser...rives/od-presure-test-524743.html#post3556520

Might help point you in the right direction.

 

[SDSeville]

Thanks Guys. I will let you know how it goes.

 

[JaCrispy]

My boat it was the seal in the upper unit the drive shaft slips into. They say not to use the o-ring on that shaft.

 

[SDSeville]

My boat it was the seal in the upper unit the drive shaft slips into. They say not to use the o-ring on that shaft.

Was that one hard to replace?

 

[JaCrispy]

Was that one hard to replace?

No. You need to remove the upper unit though. They sell a kit with that seal included but the kit doesn't come with the drive to bellhousing gasket. So get that separately.

Also, I had a little bit of a pain getting the drive back in since I didn't have an alignment tool and my engine was slightly off.

 

[SDSeville]

OK. I pressurized it to 10 PSI and I have lost 1 PSI in the 1st hour. I have read to spray soapy water and look for bubbles, so I tried that and...no bubbles. I do not understand how the seals inside the drive would cause bubbles on the outside -- at least anywhere other than the water intake or drain holes.

 

[achris]

If you have a leaky seal on the inside of the drive (water pump base, bottom of the drive shaft or shift shaft) you need to spray the soapy water on the seal... If you don't have access, take the drive apart, seal up the oil passage between the halves and pressurise one half at a time, look for the leak. Also, 10 psi might be a little high, try it at 4 or 5psi... You might find it will leak quicker.

Chris......

 

[SDSeville]

Thanks achris. What should I seal the oil passage with?

BTW, after the 1st hour, I have not lost any more pressure. It seems to be holding steady at 9 PSI.

 

[achris]

Thanks achris. What should I seal the oil passage with?

I use a bit of sheet insertion rubber and a G-clamp.

BTW, after the 1st hour, I have not lost any more pressure. It seems to be holding steady at 9 PSI.

Release the pressure and start again. Use a lower pressure and see how it goes. Did you read my 'leaks' article? If you did, you'll see I expained why a seal can leak at lower pressure and seal at higher....

Chris......

 

[SDSeville]

It held steady for a few hours at 5 PSI. Then I lowered it to 4 PSI and it held for 12 hours. I pumped it up to 15 PSI this morning and it hasn't budged in a few hours.

I will test again once it's apart, but if it still doesn't leak, is there just a standard set of seals I should change? Except for the little oil seal I change whenever I replace the impeller, I am guessing everything else is 28 years old.

I was thinking of starting with the lower shift shaft seal and upper and lower drive shaft seals. Those seem to be the ones that could possibly cause the oil to leak from the starboard drain hole.

 

[Rick Stephens]

When I did my first pressure test I ended up dumping the whole drive in a water trough and found the leak was in one of the fittings in my homebuilt pressure tester. Made my day - LOL

 

[SDSeville]

OK, so I haven't done anything since the last post in October. It is really warming up now, so I am going to get this thing fixed and get back on the water ASAP. I pressurized again and it is leaking, so I will be pulling the drive, splitting it, and pressure testing each half.

My question is -- where do I get "sheet insertion rubber" to seal the oil passages for the pressure tests?

Thanks again for all the help everyone.

 

[SDSeville]

.

My question is -- where do I get "sheet insertion rubber" to seal the oil passages for the pressure tests?

Nevermind. I was over thinking this. Any rubber plug will do... Will let you know how it goes.

 

[SDSeville]

No Title

Took the drive off to look for the oil leak and found water in the u-joint bellows. Not sure where it is coming from. I replaced the bellows 3 years ago and it still looks and feels like new. Does anyone see anything interesting in these pictures? Could all that crud around the water hose O-ring cause a leak? The leak must be pretty small/slow because I never had any water in the bilge.

 

[SDSeville]

Split the drive and pressure tested the lower unit. I actually got to use one of my favorite tools (mechanical pencil...I know...sad... but I am an accountant) to plug the oil passage. No leaks.

 

[SDSeville]

Then I looked into the upper unit and saw this. Crap, looks like it is time for upper drive shaft seals. The seal was mangled up there along with an old o-ring.





This looks like some of the harder seals to replace. Any chance I just need the lower seal?