79 H30 Strut Replacement What Sealant?

[tomgrigsby]

I have a new strut coming from Miller Island Propeller and an appointment with the yard to have her hauled April 15th. I can see the bolts and nuts at the interior reinforcing plate and maybe even be able to get to them. What sealant do I need for the new strut? Is it applied only on the exterior? Any tips on removal and replacement will be much appreciated. This is my first attempt at this. The old strut sheared at the hull BTW, so I'll only have the Y part and bolts to remove from the hull. I'll have to pull the prop of course to get the old strut off hopefully without bending the shaft since it is no longer supported by the strut.

 

[kloudie1]

If it was running when it broke, the shaft is most likely bent enough to not be visible, but enough to cause a lot of vibration ..
The problem with strut replacement is getting the new one aligned perfectly with the engine output shaft. It usually requires shimming and several trial and error assemblies before ya get it right. With a straight shaft installed into the coupling and the coupling made up, you can get a really good idea of alignment by looking at the way the shaft compresses the new cutless bearing rubber. Look at both ends of the bearing and go for the same exact uniform compression on both ends.. If you are not competent with machine alignment, get a guy who is, (Drum Point Marine?) to look it over and advise you when you have it correct to the best of your ability. That is a place where 5200 is a good choice of sealant. Good luck..

 

[Allan12210]

I used Sika Flex 292 when I reinstalled my strut. I did not want to permanently bond it to the hull as I might have to remove it again or still not have the alignment right. The Sika Flex was just to seal the holes where the bolts pass through.

Claude is right on the alignment. Since you don't know if that new strut is exaclty the shape of the old one, you should dry test its fit. I made a little V-block that I could support the shaft on inside the boat in front of the shaft log. The coupling was disconnected and the nut from the packing was unscrewed. This way you could see when the strut was right, the shaft passed through the exact center of the stern tube. A magnifying glass helps see if the rubber cutless bearing is pinched due to misalignment. If the amount of shimming required creates a large gap to the hull, wrap the strut with Saran Wrap and fill the gap with thickened epoxy. This way the strut won't be glued and you will now have a proper firm base that is aligned. Redrill the holes for the bolts and attach with the sealant applied around the bolts and holes.

Allan