Prop Shaft Noise?

[SkippyzAfloat]

My boat seems to have developed a rubbing noise after our last outing. When arriving back at the marina after a one-hour cruise, the starboard side was making what appeared to be a rubbing noise when we backed down for the marina inlet, equal to the rpm/shaft rotation. No noise when in neutral, but appears in either reverse or forward, same rate and same noise.

This is my first inboard boat so I'm not sure what to expect when it comes to cutless bearings, their required replacement interval and shaft alignment requirements. The boat had recently started with a slight but consistent vibration on the starboard side while coming up to speed that went away at planing speed.

I don't want to run the boat if this is the case. What dangers are there if I need to get the boat to another port about 2 hours away if I make the journey at 1,000rpm's "putting speed"? Will it cause further damage to the bearing/strut if I make this trip at any speed?

The boat is scheduled to be hauled out for the winter in the next month, so I don't plan any use other than the one trip before haul-out.

Any input would be appreciated! :smt100

Thanks,

Simon

 

[SkippyzAfloat]

Bump...weekend's coming, would anyone have any input on this issue?

Thanks!

 

[wingless]

A good first step is to check the alignment. When its off the misalignment will wear the dripless Strong seals and seal carrier. It's best to set this right-on.

 

[Hampton]

Can you dive it? Get underneath and try to rattle the shaft around in the Cutlass bearing. When dry docked, people lift up on the shaft/prop to try to detect play. I don't know why it wouldn't work under water.

When I bought mine, it was out of alignment. The first month, I had new Cutlass Bearings put in. The next year, I had new Strong Seals done. These transmissions do make different noises, but if it's a new noise, it may be worth looking into.

Also, if you dive it, check to see if a shaft zinc has slid down to the Cutlass. That could happen, and it could possibly give you your symptoms. If the engine is out of alignment, you would likely get the Cutlass and the Strong, as the previous poster mentioned. The vibration you described could have been a sign of the Cutlass going out, or, it could have caused it. If you had a slightly irregular prop, it could cause noticeable vibration at various RPMs, but not necessarily all of them. Either way, the wobble would cause your Cutlass bearning to wear prematurely.

I would definately dive it before I continued to run it. You may find rope wrapped around a shaft, a displaced zinc, a well worn Cutlass... If you have to make a long, slow cruise, consider tying off the one shaft and going single engine. I probably wouldn't, but I just want you to consider all options. If you had another boat along, it could be done safely. Besides, people cruise single engine all the time (when they only have one).

 

[sbw1]

Some good ideas suggested. Alignment is easy to check and the dive is spot on. We had quite a noisy vibration on our starboard side after anchoring in some fairly shallow water. I assumed we touched the bottom. Putzed home at displacement speed for an hour and had the boat lifted out of the water. There was a large plastic bag wrapped around our shaft. Removed it. Problem solved.