Proper proceedure for checking prop shaft drip rate

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Jan 22, 2008
127
Hunter 27_75-84 Wilmington, NC
Could someone please tell me the proper way to check prop shaft packing drip rate. I have a 1984 h27 with a 4 year old Yanmar 2YM15. I have been told the drip rate should be 5-10 per minute, does that sound right ? - is that checked with engine off, at idle, or at some specified RPM? Thanks
 

Clark

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Jun 30, 2004
886
Hunter 280 Lake Guntersville, AL
I think you'll find that the situation varies from boat/individual to boat/individual and to what type packing is used. IMHO, there should be no drips when the engine is off and the rate you refer to should be checked at cruise rpm. One important check is to make sure that when an adjustment is made that the packing box does not get very warm when operated for 10-20 minutes. Just put your hand on the stuffing box (not while it is turning); it should not be appreciably warmer than say the tail of the xmission as a reference.

Sorry if this is a bit fuzzy; maybe others will add their thoughts as well.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Normallly you will have NO drip at all when the shaft is not turning. When the shaft is turning 3-5 drips per minute is acceptable with traditional packing.
 
Jun 7, 2007
515
Hunter 320 Williamsburg
Drips are overrated, but you don't want it bandsaw tight either.
When replacing, tighten the big nut by hand. Tighten thin nut hard to it.
If it leaks, repeat tightening by two flats each time.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
Every shaft and packing situation will be slightly different depending upon the condition of the packing, how it was installed, seated and broken in and the condition of the shaft. If the flax is old, dried and compressed you may need more drips for it not to become hot. The condition of the shaft can also play a role if it is scored. Ideally you should be able to get to no drips at rest but this is not always possible. There are no hard and fast rules except that traditional packings need water for lubrication.

You ideally don't want more than a 20 degree differential from the water temp with a traditional packing but 10 degrees is better. This could be anywhere from 3 - 15 drips per minute while the shaft is spinning.

Gore packings can run as high as a 30 degree differential but still should drip, even if very slightly.

If you plan on re-packing Duramax Ultra-X, Western Pacific Trading's GTU or Gore GFO are the best you will find. You're really best to set it by heat than drip rate especially with old packing and an old shaft.

Adjustments should be made very carefully with traditional packings as they have no memory and once over tightenedd/compressed will not re-bound if they need to be loosened. One nut flat at a time adjustments will get you there safely..
 
Sep 30, 2009
14
Hunter 78 h30 Annapolis, MD
go to this site

Every shaft and packing situation will be slightly different depending upon the condition of the packing, how it was installed, seated and broken in and the condition of the shaft. If the flax is old, dried and compressed you may need more drips for it not to become hot. The condition of the shaft can also play a role if it is scored. Ideally you should be able to get to no drips at rest but this is not always possible. There are no hard and fast rules except that traditional packings need water for lubrication.

You ideally don't want more than a 20 degree differential from the water temp with a traditional packing but 10 degrees is better. This could be anywhere from 3 - 15 drips per minute while the shaft is spinning.

Gore packings can run as high as a 30 degree differential but still should drip, even if very slightly.

If you plan on re-packing Duramax Ultra-X, Western Pacific Trading's GTU or Gore GFO are the best you will find. You're really best to set it by heat than drip rate especially with old packing and an old shaft.

Adjustments should be made very carefully with traditional packings as they have no memory and once over tightenedd/compressed will not re-bound if they need to be loosened. One nut flat at a time adjustments will get you there safely..
got to this site, it is an excellent how to site and should answer your questions. http://www.pbase.com/mainecruising/boat_projects
 
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