79 johnson 85hp milky lower U oil

[halas]

The motor ran fine 2 years ago.
Not in use since.
Fired it up today on muffs and ran OK with pee stream and all.
But after shutting it off found lower unit oil milky brownish.
Is there a kit for all the seals for that lower unit? How many pieces if individually purchased? Can the seals be replaced with basic tools?

 

[Mas]

Re: 79 johnson 85hp milky lower U oil

Try replacing the "nylon washers" on the vent/fill plugs with new lube first before buying the rebuild kit and run the motor in the water (not on muffs)...or get the LU pressure/vacuum tested. If the washers are not replaced, they are a very common place for water to enter.

It might be an easy fix!

MAS

 

[mikewoller]

Re: 79 johnson 85hp milky lower U oil

they make a kit for this. Only thing you might need is a slide hammer to get old seals out.

 

[Benny1963]

Re: 79 johnson 85hp milky lower U oil

pressure test and drop in water ya might get lucky and have the drain srew seals or the shift shaft seals leaking .bit of those repairs are easy and cheap and the most common

 

[halas]

Re: 79 johnson 85hp milky lower U oil

Thanks, I will try that first: drain/fill plug washers and shaft seal.
Can the pressure testing be done at home or should I take the LU to the outboard shop?

 

[lindy46]

Re: 79 johnson 85hp milky lower U oil

Thanks, I will try that first: drain/fill plug washers and shaft seal.
Can the pressure testing be done at home or should I take the LU to the outboard shop?

You can buy a pressure tester on ebay for about $30 - pump it up to about 10-12psi with a bicycle pump and see if the LU holds. If not, spray a little dish soap mix on the prop shaft, fill and drain bolts, the clutch dog pawl screw and see if it is one of those. I just checked my 5.5 Johnson which had milky gear oil, and it turned out the little clutch dog screw (phillips head by drain bolt) was leaking. This can be a fun one to remove without losing the alignment with the clutch dog pawl. I VERY carefully removed it, slipped a new seal on the bolt and put it back in - luckily the pawl didn't move and it went right back in, and that solved my problem - pressure tested fine. If the pawl slips, it time to tear down the LU.

 

[kenmyfam]

Re: 79 johnson 85hp milky lower U oil

For peace of mind and if it has not been done to your knowledge then it could be time to replace the seals anyway. Otherwise put in new oil, replace nylon washers, give it a run and check again. Then you will know for sure.

 

[mikewoller]

Re: 79 johnson 85hp milky lower U oil

Did you drain the oil after running it on the muffs, or was it a milky color leaking out of the back of the prop?

 

[halas]

Re: 79 johnson 85hp milky lower U oil

It was in the drained oil only.
Since then I did the pressure testing around 10 psi and there was no leak. I even pulled the lower unit and the water pump and prop to foam test all the seals.
The drain/vent plugs were loose and lacking good washers where the water got in.
Thanks for all the help

 

[Mas]

Re: 79 johnson 85hp milky lower U oil

Besides pressure testing, a vacuum test should also be preformed.

MAS

 

[halas]

Re: 79 johnson 85hp milky lower U oil

Please send a link how the vacuum test is done.
Thanks!