Trojan Boat Forum

I have the dripless shaft seals by PSS on my boat and absolutely love them. They are great if you are carefull where you boat.
While I was a mechanic we replaced several PSS (seals) that were emergency repairs, meaning the boat was hot-footing it back to the lift where we were waiting to haul them. Each time (4), twice with the same guy, we had to un-couple the shafts, pull them back 12" and put new seals on. These boats were on a river. EVERY time there was a problem with the seals, we discovered MUD in the seal holders, which cut off the supply of cooling water. And each time the customer claimed we were full of it...... untill we took apart the various coolers and dumped out mud. These dummies were rafting-up in shallow water then starting their engines and sucking in mud through the system.
My average repair bill was around $2000
Here's the setup on my boat.... 3/8" hose coming from a barb on the oil cooler, stbd engine, goes to one side of stbd shaft seal. Then 3/8" hose continues out other side and runs to one side of port shaft seal. Then continues on to the opposite end of the port oil cooler, if that make sense! While you shouldn't be running on only one engine, if you do the water should still be pumping or sucking through both seals.
Word of advice.....always put an extra seal (not the whole unit) on each shaft!!!!!!! That way, should one burn out while underway you could put the new one on if your handy and have access.
Twice a year, as part of routine maintenance I pull the hose off the port engine to make sure there's plenty of flow from the stbd side through both shaft seals.
Instalation is a breeze, as long as you can easily pull your shaft back
I find a lot of piece of mind knowing my bilge is Completely dry, and if I should notice some water I'll know right away something is leaking somewhere.

Ron

Good post Ron , and very good info . Dripless seals are not something you put in and forget .

+1

It should be noted that consideration to the type of dripless system installation on an upgrade is very important before you buy. There are basically two types; lip seals which Ron has touched on, use two or three stationary seals that hug the spinning shaft thus preventing water from entering. I mention an upgrade situation because for this type of system to work, the shaft surface that mates with the seals must be in prestine condition or the system will leak. The other style of dripless incorporates a face seal. One part is stationary with the stern tube while the other part made of a carbon type material is clamped to the shaft and spins with it. A bellows keeps tention on the two mating surfaces that maintain a thin film of water between them. Due to the principal of surface tention, this film of water prevents water from leaking into the boat. In this type of seal, the shaft surface doesn't have to be perfect since the shaft isn't spinning in a stationary seal. As such, these are a common choice for upgrades without replacing shafts. Same systems used on PWC.

Plumbing the port and strb seals together should only be done if the seals have two plumbing ports (dual engine app). Before that option came out, connecting the two sides was done with "T" fittings to ensure both sides got fed in a failed cooling system. Some installations were plumbed off exhuast manifolds and caused issues with water intrusion in a twin engine app. When one engine's cooling system failed, water to the parallel plumbed seals from the running engine made it's way into the cylinders of the failed engine. Merc put out a service bulletin on this some time ago recommending not to parallel plumb because of this.

Thanks for the info. I have been thinking of replacing my stuffing boxes with dripless, it's good to hear 'the other side of the story' that the sales guy doesn't tell you.

I replaced my standard packing with this and am happy with little or no dripping. 1/4" of course
http://www.gfopacking.com/

X2

I have two and am installing DSS seals on both engines. Water will come from the bypass raw water on each side entering the exhaust manifold. Port and Starboard will not be inter-connected.

Thanks for the tips to check from time to time to be sure you have water flow, may put a T and hose with valve at the seal end, seems that would make it easier to check for water flow.

The F-28 has V drives and darn near impossible to repack, witnessed by mangled stuffing box when engines were removed. Some jake mechanic botched up packing gland nut threads so would not hold, he drilled and tapped a set screw to hold Gland nut, a crappy fix IMO.

My research indicates that the DSS seals with water supplied when moving over 12 mph last a very long time. Uner 12 mph water from outside will lubricate above 12 mph a vacuum pocket occurs ergo not outside lubricating water.

HOW TRUE Ron!!!! My parents Sea Ray was like that because they had it inspeted and the water wasn't cooling it properly because the boat was in salt water until now. I know what to do but fortunately enough I still have regular shaft packings on my boat and they are fine (knock on wood!)

Joe

I also installed the "Norscot" system one time, which is a system that is similar except it has a bottle like the anti-freeze overflow mounted high and nearby thats filled with transmission fluid and a single hose connected to the shaft log system. After 5 years, the old dude has had zero problems and reported only having to add maybe 2 tbs of fluid.

Ron

Ron, I was going to ask if anyone new that to be OEM. I know of two Meter expresses that have that oil feed system.