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Milky oil in L/U 1967 Johnson 40 hp electric shift

F

fishfool

Member
I have a 67 Johnson 40 hp electric shift that has milky oil in it. I have drained it, and refilled it with fresh oil twice but it still comes out milky. What can I use to flush out all the remaining water and oil. I have have the l/u off and have put 14 psi in it, in a tub of water and it will not leak, it will hold the pressure for 7 days. I have tried putting the presurre in form either the fill or vent hole, with the same results. Any ideas.
Thanks
 
Re: Milky oil in L/U

If water in oil, you may normally not get a leak from pressure testing.
Most likely one of the outer seals, driveshaft/propshaft that is leaking.
You need to do a vacuum test.
I would just have changed the seals.
 
Re: Milky oil in L/U

Some thoughts.

You have only been testing it statically. It is possible that if there is some wear in the bearings or of the shafts where the seals make contact or if either of the shafts is slightly bent it could leak while running but not when stationary.

The seals are I think primarily oil retainers. They are designed to keep the oil in but are not necessarily so effective at keeping water out! A later practice is to fit two seals on both shafts facing in opposite directions. One then keep the water out while the other keeps the oil in.

A vacuum test might well give a different result!

If it were mine I would strip it down and replace all the seals and O rings etc.

For simply flushing I would fill with a cheap automotive engine oil, give it a short run to churn it all up and then drain thoroughly. Repeat if really necessary
 
Re: Milky oil in L/U

From 40 years of outboard repair experience,-------------you need to change the seals.----------------You are risking expensive repairs to the electric shift components.---------------It appears you have the lower unit off , and likely the expertise to do the job.---------It really is quite simple to do.
 
Re: Milky oil in L/U

Thanks for the replys everyone. I have all the seals and orings needed to do the job, I was justing hoping someone would be able to shed some light on how to find the leak before I did the reseal. I will have to borrow a vacum pump when it is done to check it.
Thanks again
Glen
 
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