propshaft seal

[ddaigle]

1971 60 horse hydroelectric, rebuilt lower unit but still getting water in it. Doesnt leak oil out but did notice that propshaft had a groove in it where seals are. Can this be fixed or is it new shaft time?

 

[Paul Moir]

Re: propshaft seal

Pressure test the lower unit first with 5psi of air. Then submerge it and see where the bubbles come out. It really is the way to find leaks. <br />This can be done with a cheap pressure guage, a bicycle pump, an old tire valve stem carved to fit the oil fill screw hole, and some tubing. <br />If the groove is bad, there are alternatives to replacing the propshaft, such as a Speedi-Sleeve.<br /><br />I hope this helps!

 

[ddaigle]

Re: propshaft seal

Thanks Paul, I can handle the pressure test, but have seen posts about a vacuum test also. I have a small hand vaccuum pump, but do you have to have a gauge to tell if its leaking? Also, where can I get speedi sleeves?

 

[Paul Moir]

Re: propshaft seal

The vaccum pump is good to find out if it's leaking only under vaccum, which sometimes happens. The nice thing about the pressure test is when you submerge the lower unit, you see exactly where the leak is.<br />You probably don't need a guage since the most vaccum you can conceivably pull is 14psi. Just give it one or two pumps and see if it retains the vaccum for five minutes.<br />I expect any machine shop can install a speedi-sleeve or similair fix for you. You should be able to buy them from a local bearing supply house; I see a few places online that sell them too. They're just a thin sleave that fits over the worn part of the shaft to give the seal somewhere to ride. It increases the OD of the shaft slightly, but that doesn't make any real difference to the seal. The nice thing about Speedi-Sleeves is that they're made of stainless steel.

 

[ddaigle]

Re: propshaft seal

Thanks a lot Paul, youve been a big help.