Wanted: Shaft Seal expertise/experience

[DJK]

Re a Nordic Tug 26 with Yanmar power and traditional shaft seal. During a first-of-the-season run yesterday to check things out I took the temp. of the shaft seal packing nut. 95'F. There was, however, more water dripping - 10-15 drips per min. than I would like. Today I intended to tighten the packing nut a 1/4 turn or so but didn't as there wasn't any dripping with the shaft stationary. My understanding is that 95' is a good running temp. and that no drip when not running and 3-5/min. when running is the target.
Regarding the attached pics, my concern is about the material I found in the bilge below the packing nut—the material on the towel. I looks like pieces of packing material.

So my questions are: 1. Should I be tightening the packing nut to reduce dripping when underway even though there isn't any dripping when not running? And, 2. Should I be concerned about the bits of material found below the nut? I guess there is a third question - Am I being overly cautious about this?

 

[RickyD]

Is that cocked clamp presenting an optical illusion or are your shaft and shaft tube not in alignment?

 

[O C Diver]

To me, a great deal depends on when it was last repacked. If it hasn't been done during your ownership and you don't know when the previous owner did it, I would repack it. It can be done in the water with a towel and a couple of hose clamps to reduce the flow to a trickle.
I would do the one on my charter boat every couple of years before changing to a dripless. 20 years ago the material was under $5 and took under 2 hours.

Ted

 

[jleonard]

The general rule of thumb for temperature is 10 degrees F above ambient. Thats not to say that 15 or 20 degrees is bad, but 10 ish is the goal.

 

[Steve DAntonio]

My rule of thumb is 30-40F above ambient. What is the ambient? Is the material hard?
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