42 searay broken shaft

The fact of this case? True but my comment was meant in general...

Like how many balsa cored sea ray hulls have quietly been replaced by the factory after suffering severe damage due to water intrusion and delamination...

Or when hundreds of gas engines ingested water because they miscalculated the risersr heights...

It s not about sea ray, it s about boat builders in general often making these kind of mistakes so assuming that because a big name is behind a boat it is properly engineered just doesn't work out in the real world

So lots of good info here. I am in the ship repair business and have ben for a long time. Shafts are an area of constant concern for our customers given the scenario in a failure. The posts about checking alignment and the fit between prop and shaft are spot on and not to be taken for granted. My previous boat was a Sea Ray 390 and I also experienced an unexplained shaft failure. I do not attribute this to S/R as it can happen to any boat. The reality is that these shafts are under tremendous strain. Items can contact the prop without you ever knowing it. There can be suttle vibrations that go undetected. And yes, shaft material can have flaws in them that do not manifest themselves until years later and exacerbated by the aforementioned issues.
The best way to prevent unexpected failure is to check the running gear even if you are not aware of a problem. Check alignment, inspect cutlass bearings, do a blue fit on the props each time you pull them and I recommend a simple Non Destructive Test (NDT) of the shafts using dye penetrant and developer to look for signs of cracks or inclusions. This should be done especially where the shaft begins it's taper (weakest point) and around the key way. Here's a few pictures of my shafts being NDT'd.

Searay like any builder has had some issues but it's a small percentage of issues compared to the amount of boats they build(like any builder). The difference is that Searay (much like Cat) does step up to the plate and fix/warranty their problems without a fight. They don't build the best boat, but they build the best boat in their price range/style. They build an above average quality boat, for an average owner and average usage for an average price and they do that very well. You're not going to take a Searay and fish Marlin tournaments (although I had a customer that regularly did in St. Croix), cross the gulfstream in 12' seas, or run the boat to Brasil. Just as well, you're not going to leave Friday for Nassau from Fort Lauderdale and be back on Monday with a Nordhavn because that's how long it will take you to get there and back.

I had a 2001 Wellcraft 42' back in 2007 that had completely soft foward deck, completely soft swim platform, and 3 soft spots in the cockpit, and wellcraft told the owner to go pound sand.

I also was managing a 2003 42' regal back in 2005 that developed pea sized blisters every square inch of the hull below the water line. They offered to fix it if we ran it to and from St. Augustine, which would've cost the owner $7,000. They then offered $3500 for him and the cheapest bill from a reputable yard was $13,000.00 so the owner had to pay the difference. The same boat had VERY milky woodwork throughout and they wouldn't do anything about that.

Quote from K1W1s article;
"but had given him little information other than that ''the prop fell off''"

I still hope that's better than "the front fell off"..
,rc

I wonder, Any comments on a different sound, hum or vibration with new shaft & wheel? Or SSDD?

That will do it. I once saw a 75' Hatteras MY come into Ocean Reef many years ago. One of their engines wouldn't run in gear just neutral. A diver came out with a 13' Zodiac and pulled enough crab trap line off of the shafts that it completely filled the Zodiac like a mountain 3' high. They must have left it on Autopilot and never once went around the crab trap lines. It was unbelievable and the talk around the docks there for a long time.

Shafts do break. It s good idea to inspect them for cracks or corrosion. A year ago the boat i used to run was sold and when the wheels were pulled to be checked, an inspection revealed one of the shaft has a crack. Would eventually have failed...

You don't really need a part number. Any good prop shop can make a new shaft. There are different grades of shaft material, make sure they use the right one or maybe consider upgrading