Milky Gear Oil on Johnson 90 1994

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DavidA

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Joined
Apr 29, 2010
Messages
1
Howdy; Looking for help - I have a 1994 90 HP Johnson Outboard - whenever we take her out the gear oil turns milky (a result of water getting in?) - Looking for help as to what seals to look for - any common ones?

I dont have a manual but am looking for one if anyone could point in me in the right direction.

- I will double check on the model number and post it when I get home.

Cheers in advance.

Dave.
 
S

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Milky Gear Oil on Johnson 90 1994

Go ahead and get the OMC shop manual - forget the off brands.

You don't mention where you are seeing the milky oil. Often this is not from the gearcase but from unburned oil in the fuel. Even if you are sure that water is getting into the gearcase drain and replace the gearcase oil and make sure that you replace the gaskets on the fill/drain plugs with new. Leaking gaskets is the most common source of water in the gearcase. Water test and recheck.

If the gear oil is still milky then you will have to open it up and replace the seals - - and wa la you will by now have the OMC manual.
 
W

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Milky Gear Oil on Johnson 90 1994

If gear oil (you drained some) right? is milky, you have a leak letting water in.

The general procedure for finding leaks is
1) drain the gear oil completely.
2) pressure test (no more than 15 psig)
3) submerge LU in water, bubbles will show the leak source - choice prop shaft (2) seals, drive shaft, shift shaft plus vent/drain screws
4) vacuum test (best vacuum you can acheive), submerge
5) good LU will retain some vac/pressure for at least 45 minutes for V4 and V6 LU's

Follow shop manual for seal replacement as needed.
 
K

keynowhere

Recruit
Joined
Apr 30, 2010
Messages
4
Re: Milky Gear Oil on Johnson 90 1994

nine out of 10 times water gets in by the shift shaft seal where it enters the water pump housing. best to have a technician to replace it when you have your water pump impeller replaced. you have to run the shifter rod in and count the turns til it bottoms out and record the amount of turns,then unscrew the shifter rod. remove water pump housing and its a real pain to get that little fat shiftshaft o-ring out and back in if youve never done it.
 
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