Packless Shaft Seal

[Dave Winiker]

I just installed a PYI packless shaft seal in our '87 Hunter31. Other than a little initial difficulty in backing the prop shaft out of the transmission coupling the entire process was a piece of cake. Now back in the water and all seems AOK except for a pronounced shaft vibration at about 1500 RPM which wasn't there previously, except for the usual Yanmar vibration at about the same RPM. I've checked for loose fittings, gear adrift etc. and have been unable to pin down the source. There was very little play in the shaft and the cutlass bearing seemed to be in good condition. I suppose I could simply ignore the vibration and accompanying noise and run the engine at a lower/higher rpm, but I don't want to really screw something up. Has anyone had a similar experience?

 

[Tom La Roche]

How is your transmission allignment?

This often is the cause of harmonic vibration at certain RPM's. I have had this problem previously in my 1980 Hunter 27. Best wishes and only fair sailing to yaCapt Tom

 

[Dave Swanson]

Same problem on my H30

I installed the PYI dripless as well on my 1989 H30 and have the same vibration sound problem. It is basically the unsupported shaft vibrating against the shaft log. If you think about it, the shaft used to be supported at the stuffing box and now it is not supported laterally by the stiffing box because of the dripless PYI seal. I had the shaft aligned by an engine mechanic and it minimized the vibration sound, however, it is still there around 1500 rpm. So now I just make sure to run the engine above or below the "harmonic" vibration noise point. I have had in on our boat for 5 years and it works fine.DaveS/V Getaway

 

[Dave Winiker]

Thanks Dave; I agree with your diagnosis. Problem is that us old aviators are very much "tuned in" to every engine sound and vibration. I'll guess I'll just minimize operating in that range and learn to live it.

 

[Lee Henderson]

Just Did My 27.5

I just had the PYI packless unit installed in my boat a 27.5 Hunter with a 10GM 8hp which is known for it's vibration. After the boat was back in the water I spent the day tweking the mounts and have been able to eliminate all of the clatter except at one RPM range....it's great and I have a bone dry ship. I also did a visual inspection on shaft as it exits the shft log to make sure the shaft was centered in the log. This is easier when the boat is on the hard but it was worth the time to use this as a basic guide fir basic set upLee HendersonS/V El Sueno