Dripless shaft seal failure today

04cobra23

04cobra23

Member
Aug 21, 2014
344
Boca Raton Florida
Boat Info
340DA and 215LR
Engines
Twin 8.1's and 4.3 Merc
Well... Today was going good until I got back to my house and realized the bilge was turning on every 30 seconds. I opened the hatch and saw LOTS of water coming from the starboard motor shaft seal. The plastic fitting failed and from what I saw the elasticity was done and the seal was no longer good. We tried to set the seal further back which helped minimize the water coming in. Now the bilge is running every min versus 30 seconds. Can this be done in water or does the boat have to be hauled? What a mess. I am going to upload a few pictures. Doesn't help that I need a small child who is a trained mechanic to fit inside the engine room
 
If you have a spare seal already installed it is easy to slide it in place. If not, it's a haulout to pull the shat and install new seals. You usually install two seals so you have a spare
 
Replacing a seal if you have a spare in a carrier on the shaft is far from an easy job on a 340DA. It certainly isn't brain surgery, but there just isn't adequate room to get the tools you need down there....now add water pouring in and it is even more complicated.

Get on the phone early tomorrow and get the boat out of the water. You are one dead battery away from sinking.
 
Battery charger is on. I am going out to check on her in a min. There is an entire spare kit on the shaft or are you talking about the rotor? From what I understand the entire thing failed. Doing ANYTHING on a 340da with big blocks is a NIGHTMARE.
 
From the pictures it appears to be the older Tides Marine Strong Seal which has been replaced by the Sure Seal model. I can't tell from the pictures if there is a spare seal or not but it would be located about 3-4 inches up the propeller shaft and will have a plastic ring cover protecting it. I have replaced the seal on my Sure Seal model on my 310 but it is a difficult task (because of access to the shaft) and you need to be very careful not to score or scratch the new seal as you slide it down the shaft.

If it has completely failed then you should pull out as soon as you can and get it repaired.
 
Please excuse my lack of knowledge but, what do you mean "spare seal"? I can't see how another could get on there. In order to remove the boot you would have to cut the rotor that slides onto the shaft.
 
A spare seal is a separate ring seal that can slide into the shaft seal unit that you see in your pictures. The separate seal will sit in front of the larger unit on the shaft. You may have one or maybe not. Either way I would be pulling the boat as Frank is right--not an easy place to work under the best conditions. Pulling the shaft out makes this much less risky of a job albeit more expensive.

I'm assuming you've already 1) tightened the clamps and 2) checked that the water supply feed hose is not cracked and properly seated (not loose)? I've seen the water supply hoses crack at the end, right under the clamp. Easy fix...just cut it back and re-insert. I've never seen the entire unit somehow fail.
 
Please excuse the frank-ness here, but at your level of understanding of the mechanics here, you really need to get the boat hauled today.


To remove the seal housing, which is the part that inserts into the rubber hose connected tot he shaft log that you say is cracked, the shaft has to be uncoupled from the engine, the prop removed, then the shaft has to be partially removed from the boat by sliding it aft until the coupler end is even with the rubber hose. None of that can be done with the boat in the water.

If there is a spare seal it is in a black plastic seal carrier a few inches up the shaft toward t he coupler from the dripless seal housing. But if the housing is cracked, then the extra seal isn't going to fix the problem.....only a new seal assembly will help.
 
The plastic nipple cracked completely and the hose was just dangling. But in the pictures you can see the water leaking from the boot on what seems to be both sides. So the shaft seals basically go into the rotor? The rotor has 2 o ring seals on it. We did tighten and tried to put more pressure on the boot but nothing. This was last night, my mechanic is going this morning to see what can be done. Im sure the boat has to be pulled.
 
fwebster said:
Please excuse the frank-ness here, but at your level of understanding of the mechanics here, you really need to get the boat hauled today.


To remove the seal housing, which is the part that inserts into the rubber hose connected tot he shaft log that you say is cracked, the shaft has to be uncoupled from the engine, the prop removed, then the shaft has to be partially removed from the boat by sliding it aft until the coupler end is even with the rubber hose. None of that can be done with the boat in the water.

If there is a spare seal it is in a black plastic seal carrier a few inches up the shaft toward t he coupler from the dripless seal housing. But if the housing is cracked, then the extra seal isn't going to fix the problem.....only a new seal assembly will help.
Click to expand...

Doesn't seem to be leaking from the shaft housing. I was not understanding how there can be an extra seal kit that's what I was asking. The way that this pos system is, if you have any sort of failure the entire thing needs to be replaced (aside from the plastic nipple) on top of the genius engineering of my DA's engine compartment makes this a very difficult and expensive task.
 
Guys ......if you blow the picture up you will see water pouring out a fitting on the seal. It would appear to be either the water supply hose or the cross-over hose fitting. I'm not suggesting that the seal isn't bad because it appears to be leaking but the fitting is where the water is pouring in. The boat needs to be pulled.

John
 
IMHO, you are better off with a short haul and full replacement of both sides if they are the older model.
 
PlayDate said:
Guys ......if you blow the picture up you will see water pouring out a fitting on the seal. It would appear to be either the water supply hose or the cross-over hose fitting. I'm not suggesting that the seal isn't bad because it appears to be leaking but the fitting is where the water is pouring in. The boat needs to be pulled.

John
Click to expand...

John,

Fitting is indeed broken. That is being changed this morning and we will go from there. From what my mechanic said the boot lost its strength to put pressure on the rotor so the seal isn't strong enough to not leak.
 
When installing the dripless seal while the propeller shaft is disconnected, it is common for the the installer to slide two seals on the shaft (Tides Marine calls it a 'lip seal' but not sure about other manufacturers). The first seal is of course used in the internals of the shaft seal assembly and the second is positioned farther up the shaft from the assembly and then covered with a protective casing. If the seal in the assembly fails, it is a fairly simple process to remove the seal cover from the shaft seal assembly, remove the protective cover from the spare seal, slide the spare seal down the shaft into the shaft seal assembly, and replace the seal cover. This is all conditional based on access to the shaft seal assembly. Sea Rays are notorious for small engine rooms so access is typically difficult.
 
Guys - the poster has verified that this is not a Tides "lip seal" but a PSS unit.(according to the mechanic)

I have the tides system, but when it comes time to replace them, I'm giving serious consideration to a Lasdrop. Here's the details.

http://www.lasdrop.com/gen_2.html

One of my tides seals lost water cooling and melted. I replaced it in a rush with the same type without researching. Wish I would have taken the time to do a bit of research...
 
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