Leaking Shaft Seal

[Aerobaticflyer]

Can anyone tell me if I have to have my boat hauled out to service / replace a leaking shaft seal? I have Cummins v-Drives and the starboard engine is dripping about a drop a second while stationary at the dock. Or can it be done while in the water?

Thanks!!

 

[fwebster]

If you have a spare seal in a carrier mounted on the shaft, it might be possible to change the lip seal part of the tides seal in the water. It is tight and hard to do but it may be possible. If you elect to try this, at least have a boat yard on standby where you can get an emergency haul out in case you cannot get the new seal seated properly.

The better approach is to replace the entire seal housing, and that does require a haul out and partial shaft removal. The cause of the lip seal leak is always wear in the seal housing. It is Delrin and it must fit snugly on the shaft to keep the lip seal aligned. When the housing wears, it begins to wobble on the shaft and that lets the lip seal wobble as well. You might replace the lip seal this time, but in about a year, you will have another leak. What causes the seal housing to wear is usually sand and debris being churned up during anchoring or docking so you very likely have the same issue going on on the other side as well, so don't be surprised or alarmed when it begins to leak too.

I'm in shallow water too so I have had to deal with this a number of times in the 16 years we've owned our boat. I just replace both complete seals at the same time with one haul out.

 

[Aerobaticflyer]

Thanks Frank......since I also have a weeping rudder post I guess a haul out and both shaft seals and rudder post seals replaced on a 9 year old boat is the prudent move.

 

[fwebster]

The rudder post is an old style packing gland and it can be tightened in the water; however, if you need more packing or the packing replaced, you need to do it with the boat out of the water because all of the rudder hardware above the packing nut must be removed to get the packing nut far enough up to add or replace packing. That leaves you with nothing holding the rudder in the boat. If the mechanic slips or loses control of the rudder, it can fall out of the boat. That leave you with a 1" hole in the boat an emergency haul out, plus the cost to have a diver find and retrieve the rudder.

 

[Aerobaticflyer]

More support for a haul out.....out she comes tomorrow.