prop shaft stuffing box

Sep 3, 2017
88
Boat Info
1987 Sea Ray Sundancer 340
Engines
Dual 454 Mercruisers
531E108F-92E5-4B3F-AEEF-F5ABFCF5525D.jpeg
Question for the vast knowledge of the group. My prop shaft/stuffing box has gotten to the point where it needs to be addressed. I had the Marina look at it in the spring and they said to run it until the dripping was a steady stream as they would have to remove the exhaust/risers to get to it and would be a good time to replace at the same time. As well he said someone may have replaced the stuffing with “lifetime” stuffing and if it scores the shaft, we would have to address that as well if needed. So far they have been honest and fair with us. Here’s the question. I’d like to start by tightening the stuffing. It looks fairly easy in the owners manual other than the getting to it part. Any insight or experience regarding physically getting to them as well as the actual tightening would be appreciated. 1987 340 Sundancer
 
A leaking shaft seal on a boat with V Drives will sling water up onto the engine oil pan causing rust and corrosion that can end up with leaking oil. The installation of "lifetime" IE dripless shaft seals will require engine removal. Tightening the existing seal if you can is not an easy task. FWIW there are a couple of brands of "dripless" shaft seals I prefer Tides Marine Sure Seals over PSS seals as the PSS can fail allowing large amounts of sea water in thru the shaft log.
 
It doesnt look like you have alot of threads left to tighten that nut down. There are normally several rings of packing in there that get squished around the shaft. As the material wears/ages you find yourself tightening the nut to help compress the remaining material - which slows down the dripping. Eventually you cant turn the nut anymore or you dont have enough packing left. Not a good situation to be in.

You may also find that the packing nut does not want to move - given the looks of your setup. Everyone says to use large adjustable pliers, or an adjustable plumbers wrench (which breaks easy). The STBD side on mine would not move to save my life. I had to make wrenches and apply more force than I would have liked - but got mine tightened. This winter I have to pull them completely and clean them up. So aside from space - you may need the right tools which you will need to source. Measure the size of both nuts on the shaft.
 
Tightening it isn't too hard. Remove the pin tighten the nut a quarter turn. I have no idea what they mean by "lifetime" packing -- no such thing. If your up for the struggle, I would replace the packing with gore Tex gfo dripless packing. Stuff is so slick you can tighten and adjust by hand - no need for a wrench.
 

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