Outdrive oil drip

[sr79]

My 1999 Alpha one gen 2 has a slight oil leak at the split line. I removed the lower half and noticed lots of oil on the splined shaft. Next, I removed the upper half, plugged small oil passage to lower and filled upper with oil. Oil poured out through center hole in female splined shaft. I can see the male splined shaft goes through 2 seals, I'm thinking both seals need to be change. Now my questions: 1). why does the female splined shaft have a center hole all the way through? I don't thing my alpha gen 1 is that way because I coat the shaft with spline grease. 2). can I plug the center hole and just rely on grease for lube? Also, I see 2 slightly worn spots where the male splined shaft goes through the seals. When changing both seals should I machine .250 shim to go under the seals to move wear area to a new location, looks like plenty of room to do that?

Bottom line is I need to stop the oil leak one way or another as soon as possible. I'm a good mechanic but would like some advice before I do something I've never done before. I looked at a very good video on line for alpha one gen 1 but can't find one for gen 2 upper seal replacement, are they the same? Thank you.....

 

[achris]

Your drive shaft seals aren't leaking. The design of the upper housing is such that the lower drive shaft splines are in the main gear oil. To find your leak, reassemble the upper and lower and with The complete Stern drive unit on a stand, do a pressure test. That's the only way to find leaks. Don't start redesigning the engineering, that's not the way to fix things.

Chris.

 

[Rick Stephens]

Chris is right.... pull the upper, reassemble the halves and pressure test. As soon as you pull the lower off any oil left in the bearing pocket where the shaft pulls out is dumped making it impossible to judge by where you see oil where you might have a leak.

I would also recommend you always pull the entire drive and do your disassembly and reassembly in a bench fixture - super simple to make. This lets you do all the required annual inspections and maintenance that just pulling the lower will miss. Besides, lifting a lower up and installing on an installed upper is tough and fraught with possible seal damage, dislodged quad o-ring passageway seal or missed water tube connections.

 

[sr79]

Chris is right.... pull the upper, reassemble the halves and pressure test. As soon as you pull the lower off any oil left in the bearing pocket where the shaft pulls out is dumped making it impossible to judge by where you see oil where you might have a leak.

I would also recommend you always pull the entire drive and do your disassembly and reassembly in a bench fixture - super simple to make. This lets you do all the required annual inspections and maintenance that just pulling the lower will miss. Besides, lifting a lower up and installing on an installed upper is tough and fraught with possible seal damage, dislodged quad o-ring passageway seal or missed water tube connections.

Thank you for your quick response. I did everything you suggested, reassembled both halves on my bench with good quad ring in place, set my compressor at 15 PSI, used oil fill attachment connected to air hose and pressure tested both halves as a unit. Borrowing my grandkid's bottle of Miracle Bubbles and using an acid brush I was able to blow great big bubbles where the male splined shaft goes into the upper. Maybe I do need to change the 2 shaft seals after all. Now, what's my next step? Pull the input shaft ass'y, and vertical shaft so I can access the seals? Thanks for your help...
Dennis

 

[Rick Stephens]

Here's the relevant pages from the manual:

 

[Kubaat3lover]

Hello All, i dont want to hijack this thread but ive got simple question.
I did pressure test (5and15psi) on my Alpha G2 with no leaks but Ive tested the whole drive, not separated.
Should it be done as a whole unit or separated? If separated how to keep it pressured?
Im asking because in 6 months (summer season) my drive lube from full goes to the minimum level then it stays for ever..
Boat in the water.

 

[achris]

Hello All, i dont want to hijack this thread but ive got simple question.
I did pressure test (5and15psi) on my Alpha G2 with no leaks but Ive tested the whole drive, not separated.
Should it be done as a whole unit or separated? If separated how to keep it pressured?
Im asking because in 6 months (summer season) my drive lube from full goes to the minimum level then it stays for ever..
Boat in the water.

Yes, please start your own thread, or do a search, this subject has been well covered.

Chris.
iboats mod team.

 

[sr79]

Thank you for your quick response. I did everything you suggested, reassembled both halves on my bench with good quad ring in place, set my compressor at 15 PSI, used oil fill attachment connected to air hose and pressure tested both halves as a unit. Borrowing my grandkid's bottle of Miracle Bubbles and using an acid brush I was able to blow great big bubbles where the male splined shaft goes into the upper. Maybe I do need to change the 2 shaft seals after all. Now, what's my next step? Pull the input shaft ass'y, and vertical shaft so I can access the seals? Thanks for your help...
Dennis

No more oil drips! - I changed the spline shaft oil seals, install new water pump kit and quad seal. Inspected and cleaned both upper and lower, reinstalled outdrive and now everything is working as it should.
Thx Dennis