changing seals johnson 18hp

jdsgrog

Chief Petty Officer
Joined
Jun 19, 2007
Messages
480
I've been searching the forum, but I don't seem to have a good answer. I am changing the seals on my johnson '59 18hp motor. I bought the seal kit from iboats and it seems to come with two drive shaft seals where my motor only had one. What is the proper way to put the seals on?

1. Do you need to use both new seals to replace the old or just one?
2. If you use both, how do you put them in? In which direction do the seals face?
3. If you use only one, does the open face (the side with the spring) face up or down?

Any help will be welcome.
 

Daviet

Fleet Admiral
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Sep 24, 2008
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8,958
Re: changing seals johnson 18hp

Sometimes the kits fit several different models and there might be extra parts left over. The parts breakdown I looked at shows only one seal. If I remember correctly, the spring on the seal faces out, towards the prop.
 

jdsgrog

Chief Petty Officer
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Jun 19, 2007
Messages
480
Re: changing seals johnson 18hp

Thanks. Does this go for the drive shaft as well, the spring side pointing upward towards the water pump?
 

F_R

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Jul 7, 2006
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28,195
Re: changing seals johnson 18hp

First off, think about this: The original seals were single lip, very effective in one direction and only marginally effective in the other direction. So they were installed with the lip/spring toward the oil to keep the oil in. In later years, many models have two springs installed back to back. This keeps the oil in AND keeps the water (and dirt) out. So if you got them and there is room for them USE them!!! Install the first one with the lip toward the oil side, followed by the second one with the lip toward the water.
 

kfa4303

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Sep 17, 2010
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6,094
Re: changing seals johnson 18hp

I just replaced the seals on my '66 20 hp (same motor) and while the kit did come with 2 prop shaft seals and 2 drive shaft seals, there was only room for one of each. Be sure you put a bit of gasket sealer around their perimeter and tap them into place. Using a socket once size smaller than the circumference of the seal itself will help to seat it evenly. Here's a handy link too.

http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation
 

jdsgrog

Chief Petty Officer
Joined
Jun 19, 2007
Messages
480
Re: changing seals johnson 18hp

Thanks everyone. F_R, I did read about the double seals some time ago, but I couldn't find the thread. Thanks for clarifying. I'll take a look to see if I have space for two on the drive shaft and prop shaft since the kit came with two of each of these. If there is only room for one, so be it.
 
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