59' 18hp Johnson Prop Seal

r7069c

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Was curious if anyone could tell me how to change out the prop seal on my 18hp Johnson? It's 1959 model. I can't imagine it being a tough job, I just have never done any work on an outboard motor before.
I was guessing i might need a special tool of some sort.
Also, My mechanic wants to charge me $85 to replace the seal. Is this a fair price given that I would be supplying the parts.
Thanks
Ryan
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

lil help. I don't understand the manual
 

samo_ott

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Re: 59' 18hp Johnson Prop Seal

It's tricky but if you remove the prop shaft you can get to it. A seal puller helps a lot also...
 

lindy46

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Re: 59' 18hp Johnson Prop Seal

The easiest way is to drop the lower unit, but you can try to do it without dropping the L/U. You have to remove the skeg to separate the gearcase, and to remove the skeg you have to remove the (dreaded) Phillips head screw to release the shift yoke. Then remove the 8 or so bolts that hold the skeg on to the L/U. Once the skeg is off, you have access to the gears/seals. Pull the entire propshaft assembly out of the L/U and slide the propshaft seal/bushing off the end of the shaft. There should be two small holes in the bushing where you can insert a punch to gently tap the seal out of the bushing. Alternate taps between the two holes until the seal pops out. Press the new seal into the bushing and replace in reverse order. You will also need a new spaghetti seal - I'd just buy the whole seal kit for about $20. Put some Form-A-Gasket on the spaghetti seal area before putting together. Put the skeg back on, and hopefully the Phillips head screw will fit back in and go through the hole in the shift yoke. Lay the motor down and shine a light in the hole. Use a small probe or nail to line up the hole in the shift yoke, then re-insert the Phillips screw. If you can't line the hole up, then you have to remove the lower unit to do the job.
 

tmcalavy

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Re: 59' 18hp Johnson Prop Seal

Good advice so far. If you haven't worked on an outboard before, I'd pay the guy $85 to do the seal as long as you get to watch...provided you are interested in doing your own work. If not, pay the $85 to have it done as long as you know this guy does good work. Maintaining an outboard isn't tough, but doing your own work requires some skill and some willingness/time to learn. If you're not interesting in doing your own work/wrenching, pay to have it done.
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

Thanks everyone!. I want to do this myself. My mechanic does great work but I have always tried to work on all my vehicles if at all possible. The only thing stopping me in the past is special tools.
This forum is great.
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

Ha. Ran into first problem right off the bat. One of the phillips screws that hold the skeg is stripped. Any advice on getting that off?
 

wilde1j

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Re: 59' 18hp Johnson Prop Seal

You got lucky! Most of us won't touch those screw extractors BC they tend to break off, leaving a worse problem than you originally had.
 

lindy46

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Re: 59' 18hp Johnson Prop Seal

An impact screwdriver, the type you hit with a hammer, helps get those skeg bolts out. Just did one this morning - dropped the L/U, removed the skeg, replaced the faulty seal (in my case it was the shift rod seal) and had it back together in about 2 hours. Pressure tested and no more leak!
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

Finally,
Got everything apart. I cant figure out how to get seal from inside the bushing out. I may be off on my terminology but i have some pictures posted.
There is a brass cap that I took off the bushing. The cap is laying next to the bushing. The seal is just inside. I may be wrong but is that not the prop seal?
The pictures are on the links below
http://pissantfarmers.net/aboat2.jpg
http://pissantfarmers.net/aboat3.jpg

To me it seams like you need some kind of puller to get the seal out. I read the instructions above but there is only one hole on the side of the bushing.

Please help.
Ryan
 

lindy46

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Re: 59' 18hp Johnson Prop Seal

Sure doesn't look like the prop shaft seal to me?
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

Well I changed out the seal that was inside the bushing by first removing the brass cap with a small screwdriver. I just genty wedged the screwdriver in between the bushing and the cap. The cap cam right off. Just inside the bushing was the seal. I turned the bushing upside down and used a screwdriver and hammer to knoch the seal out of the bushing. I switched back hitting the right and left sides. It finally worked its way out. I used a spark plug socket to press the new seal back into the bushing. I put everything back into place and no more leak!
thanks everyone.
 

r7069c

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Re: 59' 18hp Johnson Prop Seal

Step by Step instructions for replacing prop seal on a 1959 Johnson 18hp outboard.

1. Drain Lower unit of oil then Remove Propeller.
2. Remove Skeg . The skeg is most bottom part of the lower unit. It is attached by 9 screws. There are 8 screws on the bottom and one on the side.
3. Remove bushing. The bushing is located on the prop shaft. It should pull right off the shaft.
4. Remove cap off bushing. I used a small screwdriver to wedge the cap off by gently tapping the screwdriver with a hammer.
5. Remove Seal from inside bushing. After you remove the cap, the Seal is now exposed. To remove the seal you need to push it out. Again, I used a small screwdriver and hammer. I am sure there is a proper tool for this but my method worked just fine. Place the bushing on flat wood surface with seal on the bottom side. Point the screw driver through the top hole of the bushing at an angle. Push it downwards until you reach the plastic?s of the seal. The screwdriver should catch on the inside of the seal. Hit down on the seal. Then do the same thing on the opposite side of the seal. Repeat this until the seal has worked out until flush with the bottom of the bushing. You should have to use some pretty good force to get it moving. I then placed the bushing in a wood vice to knock the seal the rest of the way out.
6. Insert Seal into bushing. I used a spark plug socket and a hammer to press the seal into the bushing. I placed the bushing on a wood surface with side where the seal goes up. I put the seal into place on top of the bushing and pressed down with my hands and wedged the seal into place at a level position. I then took the spark plug socket and placed it on top of the seal. I gently hit the top of the socket to press the seal into the bushing. Once the seal is seated all the way into the bushing the hard part is done.
7. If you bought the seal package http://www.iboats.com/mall/partfind...gd_poid=110559&gd_row=13&**********=226867751 You should replace the bushing seal as well. The bushing seal is on the outside of the bushing.
8. Put the bushing back on the prop shaft with seal side closest to the propeller. There is a hole in the bushing that should line up with a pole protruding from the Lower Unit casing.
9. Put some gasket sealer on the skeg where the spaghetti gasket goes. Cut the spaghetti gasket to fit in the groove of the sgeg.
10. Line up the yoke screw correctly with the skeg almost in place. Once you have the yoke screw lined up put the skeg back into place. You will probably have to jostle it around a little to get back.
11. Put all the remaining screws back in.

Here are some pictures of the bushing just after removing the cap.
http://pissantfarmers.net/aboat2.jpg
http://pissantfarmers.net/aboat3.jpg
 
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