18hp Johnson FD-18e (1964)

[MPH1234]

I've have been getting water in the lower unit of my 18hp seahorse. I have replaced the O ring, half seal, seal the prop shaft goes though and I'm still getting water in the lower unit. It looks to me that it's not the best design because the six screw are on the inside of the half seal. The only other thing that I havn't checked is to see if there is any seals around where the shifting rod and the shaft that turns the gears. Is this a common problem with this model motor. tanks for any info.

 

[JB]

Re: 18hp Johnson FD-18e (1964)

The most common cause of water intrusion is failure to use new gaskets on the Drain and Vent plugs when changing gearcase oil.

 

[MPH1234]

Re: 18hp Johnson FD-18e (1964)

I also replaced those to.

 

[samo_ott]

Re: 18hp Johnson FD-18e (1964)

Yes, there is a rubber O ring for the shift rod that is behind a bushing that needs to be changed. Also change the drive shaft seal if you're in there. You should do them all. And I agree that the spaghetti seal is not the greatest but it is not usually the leaking area if you put the right goop on it.

 

[kfa4303]

Re: 18hp Johnson FD-18e (1964)

Ditto what everyone else has said. This link, http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation , may help you get at the shift rod seal and other LU seals you may be having trouble with. I just did a reseal job on my motor using the link,and it went pretty well. So far so good. However, bear in mind that this motor is almost 50 yeas old. It may be difficult to ever get the LU perfectly air tight again. If worse comes to worse, you may have to resign yourself to changing the gear oil a few times a season. Not ideal, but easier than driving yourself crazy trying to make a 50yr old LU air tight. A new/donor LU is always an option too. Good luck. Keep us posted.