Prop Shaft Seal 1973 Johnson 40hp

[BoatingCop]

I have the factory service manual for my 1973 Johnson 40hp but it doesn't specifically say how to change the prop shaft seal. Its shows how to get the gears out by slitting the gear case. Is there a way to change just the seal without taking the bottom half of the gearcase apart? I'm doing this due to milky LU fluid coming from behind the prop shaft. Thanks

 

[F_R]

Re: Prop Shaft Seal 1973 Johnson 40hp

Sorry, you have to split the gearcase and shuck the parts out, as per your manual. The seal is pressed into the inner side of the seal housing.

 

[BoatingCop]

Re: Prop Shaft Seal 1973 Johnson 40hp

Alright. Thanks for the info. Also, in the manual it says to have the impeller keyway facing aft and the #1 piston to be at TDC to avoid breaking driveshaft. Does the driveshaft only go in one way?

 

[F_R]

Re: Prop Shaft Seal 1973 Johnson 40hp

Well, now that dredges up a topic that I barely remember. I don't even remember the reasoning behind it, and to me it doesn't make any sense. They put those shafts in any old way for umpteen years without problems. But go ahead and do it according to the manual.

 

[jasper60103]

Re: Prop Shaft Seal 1973 Johnson 40hp

Sorry, you have to split the gearcase and shuck the parts out, as per your manual. The seal is pressed into the inner side of the seal housing.

Eric,
once you take the gear case apart, I was able to pound out the seal through the holes, using a hammer and nails. Bent a few, LOL. But it worked.
Also, you can press in the new seal with a hammer and block of wood.