Dripless Shafts Longevity

midexp

Active Member
Oct 5, 2016
423
Harrison Township, Michigan Lake St.Clair
Boat Info
1999 40' Sundancer
Engines
454 merc
All,

Two questions. I've had my 1999 for 3 years now. Dripless shafts still working great. I'm guessing they're original? They have a blue shaft log. Wondering how long they will last? Also, what is this black puck over the prop shaft?

Thanks

20191018_125825_Burst01 (1).jpg
 
Tides seal longevity is almost totally dependent on where you boat, docking conditions and depth of water. If you are not careful, boat over a sandy bottom, docking in shaliow water over a sandy or silty bottom all shorten seal life.

We’ve had CSR members brag about a 10 year seal life, others are happy with 5.

I am in NW Florida with a slip in 4 ft of water over a sandy bottom. We typically anchor in 5-6 ft of water over a sandy bottom and I never gotten more than 5 years out of a shaft seal. And, for what seals cost, that isn’t enough.

There are lots of variables......size of boat, diameter and pitch and pitch of props, gas or diesel, etc.
 
Tides seal longevity is almost totally dependent on where you boat, docking conditions and depth of water. If you are not careful, boat over a sandy bottom, docking in shaliow water over a sandy or silty bottom all shorten seal life.

We’ve had CSR members brag about a 10 year seal life, others are happy with 5.

I am in NW Florida with a slip in 4 ft of water over a sandy bottom. We typically anchor in 5-6 ft of water over a sandy bottom and I never gotten more than 5 years out of a shaft seal. And, for what seals cost, that isn’t enough.

There are lots of variables......size of boat, diameter and pitch and pitch of props, gas or diesel, etc.

I remember you posting this more than once Frank, the sand part in particular. I would have to think that gas vs diesel would make a difference also as too longevity since the gassers turn more rpms per hr.
A worn shaft sealing surface seems imitate in a sandy environment. Your thoughts?

Edit; does anybody make a shaft sleeve yet?
 
I have the old Tides seals. I think are called "Tides Strong Seals" and they were on the boat when I bought it in 2010. I've run them about 500 since and they still have not leaked and the spare seals are still there inside the spare seal carrier. I am a believer in the Tides brand as they are unlikely to fail catastrophically like seals that rely on spring pressure to maintain a seal.
 
And on another note--My last boat, 1989 390 ec had PSS dripless on it. I slip in 36" silty bottom , boat in Barnegat bay and anchor on weekends in 24" to 30" sandy shoals. (boat draws 24") . Those dripless lasted 11 years, not any problems before I sold.

So impressed with them the day after I closed on my current 420 I had them installed and 4 years now, same boating areas, except now I draw 30", and not a hint of a problem. totally dry.

Highly recommended----- PSS
 
Mitch,

I believe the difference in gas vs diesel (and this is just Frank's theory based on 5 sets of Tides seals in 20 years in NW Fla over a shallow sandy bottom) is in the torque a diesel generates that allows the diesel to turn a larger diameter prop with more pitch. If you and I were to anchor side by side in 6 ft of water over a sandy bottom, your props would likely not stir up a noticeable amount of sand/silt off the bottom, whereas, my boat with 24" X 24" props installed at a significant down angle would generate a dense cloud of sand spread 25ft in all directions before the sand settles. Any that gets under the boat would be sucked up in the 2" seawater intakes sending the entrapped sand directly into the seal cooling lines.

The death nell for the Tides seal design is wear between the lip seal in the front end of the housing and the shaft which would eventually wear out the seal. The real cause of the wear, however, is when sand wears away enough of the Delrin seal housing that it no longer stays centered on the shaft. When the housing wears enough that the seal develops some measurable run-out on the shaft that means the lip seal has worn to a point in its ID where it no longer seals against the shaft and water leaks past there lip seal.

So, based on the above causation factors, I don't see how a shaft sleeve could help since it is either the housing or lip seal that wears, not the shaft.

The Tides folks are great and their customer service is excellent. I can't change the factors that cause the Tides seals to wear out.....shallow water, sandy bottom, anchoring in fairly shallow water so we can access the beaches and docking in shallow lagoons where marinas are located......so last year we changed to a carbon block type of seal and, so far, are having good results, no leaks and no noticeable wear on the seal components.

As far as catastrophic failures go, we are seeing more of such failures on tides products than on other designs. The simple reason is that when the Tides seals cooling water flow stops, the seal body is going to fail and it can be ugly. The seal body easily becomes a distorted plastic mess as the uncooled shaft generates enough heat to melt the seal housing. The last one we saw fail required the Coast Guard to deliver a crash pump to pump out the boat and keep the bilge water level manageable until the boat could be lifted by a travel lift and blocked up in a boat yard.
 
Never heard of a Tides "meltdown" before. We had a 44ft Silverton with diesels almost go down when a PSS seal failed on his way back from Nantucket. Rare in this neck of the woods. The most common problem I've seen is on v-drive boats shaft misalignment causes the seal to spray water on the bottom of the oil pan causing it to rust out and leak oil.
 
Never heard of a Tides "meltdown" before. We had a 44ft Silverton with diesels almost go down when a PSS seal failed on his way back from Nantucket. Rare in this neck of the woods. The most common problem I've seen is on v-drive boats shaft misalignment causes the seal to spray water on the bottom of the oil pan causing it to rust out and leak oil.

Interesting reference to the Silverton. The only failures I have heard of with PSS come back to the installation or someone did not use new set screws if they had to move the collar (for example to replace the shaft). I have not heard of a single PSS bellows failure.

For reference purposes, I wrap the shaft with electrical tape at zero compression point and then compress the bellows 3/4" from the edge of the electrical tape. I leave the electrical tape on the shaft so that you have a visible reference if the collar slips.

In regards to the set screws....this is where people mess up. Reusing the set screws is risky. There are two screw holes on the collar. You put a set screw in each one, compress the collar and tighten the set screw to 6-8 foot pounds of torque. Then you install another set of set screws on top of them.
pss-set-screws.jpg

From PSS

Can I re-use my set screws when making an adjustment or removing the PSS Shaft Seal?
Answer: No. The set screws provided with the PSS Shaft Seal are cup-point set screws, which compress onto the shaft when tightened. Any re-use of the set screws will not allow for the cup point to properly lock onto the shaft. The PSS Maintenance Kit comes with five new set screws included.
 
I've had strong seals on 2 different boats for 18 years and approx. 2,500 hours of boating and only had one seal leak.
 
OK thanks for the feedback. I learned I have the early version of the Tides. And because they did not change over to the current design until about 2001 and I have the old design, I'm thinking mine are the originals. So I still don't know if they are destine to fail, or if it's not that uncommon to get that many years out of them. Perhaps the spare seals have already been replaced?

On a similar topic, while Googling this topic I came upon a thread from CSR about a guy who's dripless shafts were leaking. He wasn't at all familiar with them and was asking for help. I'm sure Frank remembers this one. He was advised to pull the boat ASAP to avoid sinking (if the batteries died). Boy, what a series of threads followed that one.

Anyway, I see LMBoat got 2500 hours out of 2. Hope that will be my case. Just don't know how common that is.

BTW, with the Great Lakes water level crazy high, there are literally no shallow areas on Lake St. Clair, so sucking up sand lately has not been a concern. And before the high levels, I was always careful to avoid shallow water.
 
OK thanks for the feedback. I learned I have the early version of the Tides. And because they did not change over to the current design until about 2001 and I have the old design, I'm thinking mine are the originals. So I still don't know if they are destine to fail, or if it's not that uncommon to get that many years out of them. Perhaps the spare seals have already been replaced?

On a similar topic, while Googling this topic I came upon a thread from CSR about a guy who's dripless shafts were leaking. He wasn't at all familiar with them and was asking for help. I'm sure Frank remembers this one. He was advised to pull the boat ASAP to avoid sinking (if the batteries died). Boy, what a series of threads followed that one.

Anyway, I see LMBoat got 2500 hours out of 2. Hope that will be my case. Just don't know how common that is.

BTW, with the Great Lakes water level crazy high, there are literally no shallow areas on Lake St. Clair, so sucking up sand lately has not been a concern. And before the high levels, I was always careful to avoid shallow water.

One of mine just started to drip a little at the end of the season, about a half cup of water in a couple hours of running. I will replace them in the spring. They’re original with a whole lot of use. I guess it’s hit and miss.
 

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