Prop damage

[Legacy]

After more than two decades of owning boats I finally hit something submerged. My port wheel really whacked something and I now have distinctive vibration when I run that engine over 1200 rpms. I'm sending a diver down today to remove the prop to see if it can be fixed. I have a spare. A few dumb questions. How can I tell if the spare prop I have is for the port or starboard engine? I have twin Cummins 370s. How can I tell if they are counter rotating? I drove the bloat home on the starboard engine with minimal drift. I checked the bilge, shaft seal and there is no water coming in at all. Oil pressure and temp spot on. What else should I check? Can I check the shaft myself or do I need a pro to make sure it's fine? Thanks!

[Mariner]

It doesn't really matter, since it's more likely that your shaft is bent than your prop.

[Legacy]

Bent shaft can't be good. Is that a haul out/expensive repair? Hate to be out of commission with our short season quickly coming to a close (and it's peak tuna season!) Hope it's just the prop.

[Mariner]

Yep. I can't see any way of removing the shaft without hauling the boat. Your diver will be able to tell you if it's the prop or the shaft.

What you do is simply remove the prop, and put the engine in gear. If the prop spins true, you're fine. But if it wobbles at the end, it's obviously the shaft.

More often than not, it's the shaft. It makes sense when you think about it . The shaft is thinner and more easily bent than the propeller.

[TD]

I have twin 370 also. The prop should have a "P" or an "S" stamped on the hub. They are cone shaped with key so your diver will need a prop puller. Not an easy task under water. I would bet that the diver will easily determine if a blade is bent if you have a lot of vibration. Shafts should be 1 3/4" diameter Stainless and don't bend easily. If the prop is true then the boat has to be hauled and the flange out of the engine transmission disconnected, slid out, remove the shaft flange and pull the shaft. Take to a good machine shop to true up.

Good luck.

[Merry Kate]

More than likely, a right-handed prop is on the starboard, left-handed on port.

I agree with TD: it takes an awful lot to bend a 1 3/4" aquamet shaft. Hopefully it's just your prop & your diver will have up & running in no time!

[Pitou]

Legacy, Attached is a link to H & H Propellar Shop in Salem, Massachusetts. They also have shops in Essex, Ct and Brunswick, ME They fabricate shafts and provide tuned props for Albin and many other manufactures. They provide pick-up and delivery at most marinas throughout New England. Quite the facility. I have visited their Salem plant and man oh man do they turn some huge props. Saw one that had to be 12 ft tall. They know our runnning gear.
http://www.hhprop.com/contact.html