Servicing LU on '71 hydroelec 60hp

[karrick]

<br /><br />Would this seal kit found here include what I need to reseal the lower unit? I checked my LU fluid before installing my new prop and found it to be the infamous milky color that no one likes to see. Also would it be reccomended to totally dissasemble the lower unit or just replace the seals <br />Karrick

 

[ledgefinder]

Re: Servicing LU on '71 hydroelec 60hp

Try seeing where it's leaking first. Sometimes it's just the plastic gasket on the drain screw.<br /><br />Pretty easy to convert an automotive pressure/vacuum tester. All you need is a fitting for the drain screw hole. Then pressurize the lower unit (not too much - 10psi is plenty), then dunk it in a tank of water. Usually you'll see bubbles coming from where it's leaking. <br /><br />If you don't see any, it's probably just the drain screw. However, occasionally it has a vacuum leak - that is, the seals let in water when the gearbox has negative pressure.

 

[karrick]

Re: Servicing LU on '71 hydroelec 60hp

I talked to the local service shop tech last night, and he said that unless you see water come out of the LU drain hole after the motor has been sitting vertical for at least 48 hours, the LU is fine. He said more often than not the fluid can turn a milky color by churning the air that is in the LU into the oil. On a side note, he said they don't service any of the old electric shifts anymore because Johnson does not make replacement parts if excessive wear is found.Hmm...<br /> I replaced the fluid(OMC premium blend) and will give it a check out 48hrs after my fishing trip this weekend and see what the verdict is.