[Mack]

What is the process, how difficult is it, how much does it cost to replace/repair a leaky main shaft seal?  Thank you for your input and support!

[Uhehner]

Are you asking about the prop shaft seal   If so just install GFO packing and your problem will be gone forever. Perhaps you just need to tighten the packing nut. The cost of the GFO packing is about $10 per shaft. The labor depends on how difficult it is to get to the packing gland. A good man should be able to do a shaft in 1 hour if it's accessible. GFO packing will last for years without any adjustments. Google the job on-line if you plan on doing it your self.  Capt. George

[Chris Burkard]

If you are talking about the hull/shaft seal you have to determine what type it is. What Tiara do you have and what year? Tiara began using dripless shaft seals in the mid to late 1990s. Some of the early ones were oil cooled. Soon after Tiara switched to PSS (water cooled - much better design) dripless shaft seals. If these are the type you speak of, I would ask why are they leaking? The PSS seals are great, but they require balanced props and laser straight shafts to ensure their longevity. They use a spring loaded bellow with O-rings and a collar. The Collar has to be compressed and then the set screws tightened. Word of warning, if your mechanical skills are not top notch, I would hire a professional. I have seen boats almost sink due to an improperly installed shaft seal . If the bellows are compressed properly and the seals are still leaking, then they will need to be replaced. The boat has to be hauled out of the water in order to replace them. I would also check the shaft alignment and have the props tuned and balanced. Why spend $2,500.00 to replace seals only to wipe them out in a month or so due to a vibration.

If you have the oil seals, I would replace them with the water cooled ones.

If you have the old flax style packing glands, You simply tighten the packing nuts a bit until the leak slows to a drip. If the nuts are all the way tight, you back them off, add flax and retighten them till you are down to a drip. Go to U-tube and search for it. I'm sure you find a video on it.

Good luck!

[jmk]

If packing, I agree with Capt George. Go with GFO.