1955 evinrude lower seal

[cbouchard]

i hope it is within protocol to start a new thread on the crankshaft seal replacement on subject motor. The advice that I have received so far has been outstanding. So, I replaced the upper seal with no problem. Because this is one of those motors that has the lower seal problem and the seal is the same top and bottom I was expecting to see about the same configuration when I took the power head off..but I found something different, a lock clip and spring..see the attached picture..is it possible that this motor was retrofitted with the carbon seal or is the seal I expected just down under the spring? Also the gasket had no gasket compound on it and there is a piece missing. See attached picture. The symptom that I was experiencing was a lot of green tinted oil, water mix dripping out of exhaust. You can see it around the drive shaft in artached picture. So my questions, does this possibly have a carbon seal and would the broken gasket installed without gasket sealer result in the green oil water mixture that comes out of the exhaust. If it is a carbon seal do you know the part number and can it be installed without splitting the case. Thanks, cliff. Ps having trouble uploading pictures says too big..will work on it and send seperate

 

[cbouchard]

[No message]

 

[racerone]

That clip and spring hold the carbon seal in position.-----A very good and reliable set-up it is.

 

[F_R]

That motor has been upgraded to the carbon seal. I guess it might be ok, as long as you have come this far, to remove the snap ring and pull the seal off to make sure it was done properly with the correct bearing. The bearing should have a shiny flat surface that the seal rubs against as it rotates.

When you reinstall the snap ring, notice that one side has sharper edges than the other. Sharp-edged side faces you when you put it on.

If everything checks out, put it back together and feel better. Notice that the missing piece of the gasket matches with a void in the casting, so it doesn't seal anything anyhow. Personally, I'd put some gasket sealer on the gasket.

 

[cbouchard]

Got it off..shinny bearing so that is ok...inner carbon ring cracked in half so guess that is why it was leaking?? Do you by chance have the carbon seal part number? Thanks cliff

 

[F_R]

Carbon seal is 302538
O-ring inside carbon seal is 302540
Optional quad ring inside carbon seal is 305098 (better)

 

[cbouchard]

Is the quad ring in addition to the o ring or does it take the place of the o ring..I do not remember seeing the o ring when I took it apart but it might be stuck up there somewhere..you are the best, cliff

 

[F_R]

O-ring is in a groove inside the carbon seal. Must be in there, or the carbon seal is doing nothing.

Original setup used an o-ring, changed to a quad ring sometime in the 1960-ish years. Use one or the other, cannot use both. The engineering on the change is due to the requirement that the carbon needs to stay in contact with the bearing while the shaft can move up and down within the limits of the top and bottom bearings. A quad ring is better suited to sliding on a shaft than an o-ring which tends to roll rather than slide. Either one is acceptable, just that a quad ring is slightly better.

In case you are wondering, an o-ring is round in cross section, while a quad ring is square in cross section with sealing rings on the corners. If you were to cut one in half, it would look something like this (picture)

 

[cbouchard]

Thank you very much!! Cliff