Jamming cutlass bearing

[alangoose]

When I hauled my Amel sailboat last spring I checked my cutlass bearing to find it solidly resisting my effort to turn the prop when the boat is out of gear. I have been cruising for 30 years & have never had this happen before. I installed the bearing 7 years ago & so far it has hung in there without appreciable change each time I do the classic up & down check for looseness. Now turning the shaft at all is very difficult & when it does move there is a loud squeal from the area of the cutlass bearing. Has anyone had this happen to them? Any ideas on what is wrong.

Alan

[skipmac]

Hi Alan,

I have to admit this is the first time I've heard of a cutlass bearing getting tighter over time.

Any chance something is jammed in the bearing between the rubber and the prop shaft? Could be a barnacle, sand (been shallow water or run aground lately?) or other.

Have you tried squirting some lube into the bearing to see what happens? I would use olive oil or something guaranteed safe with rubber and plastic materials.

[JeffBurright]

The first thing that came to my mind is engine alignment with your prop shaft. If you're cockeyed at all, I suspect it would prevent the shaft turning in the bearing like you describe. When is the last time you broke apart your transmission/shaft coupling and checked your alignment? Had you been noticing any vibration where the prop shaft enters the stuffing box before this problem presented? Another thought might be a bent prop shaft, but I think you'd know if you got a line wrapped around it or anything like that.

We had poor alignment on our boat, and over time it caused the transmission output coupling to lose all the little teeth that hold it on the engine. Our whole shaft fell right off the back of the engine while we were 20 miles offshore (with coupling still mated, which fortunately prevented the shaft from falling completely out of the stuffing box). It made for an interesting trip back up the narrow channel into La Paz.

Good luck!

[Oceansailor]

I have heard about that happening to boats that have been sitting in the marina a long time.

In some marinas there are marina growth that can stiffen up both cutlass bearings and rudder bearings.

[alangoose]

skipmac
Thanks for the prompt reply.

Yes I have not had this one before either.

I worked on loosening it up over a few days including using strong hose pressure squirting into the 2 seawater intakes into the stern tube, squirting a variety of lubricants into the same intakes & reversing the squirting up the stern tube thru the ribbed with the packing gland opened up & the seawater intakes closed, all to no avail - still extreme resistance to prop shaft turning!! Of course there may still be something jammed in the bearing between the rubber and the prop shaft but???

The boat has now been out of the water for the whole summer so I will be testing again in a few weeks.

Alan

[alangoose]

Jeff:

Re: Jamming cutlass bearing Thanks for the prompt reply.



I had no indication on any problem from the performance of the boat before haulout but I was stuck in the intercoastal on a mudbar & needed to wait for the famous 7' tidal range of before Towboat US could get me off. It is possible sludge could have gotten up the stern tube as I reversed strongly to get off the bar but the resistance to prop shaft turning was so persistent.


I will have to check for engine alignment with the prop shaft when I return to the boat in a few weeks.

[Oceansailor]

The problem is if you do not clean directly when the boat comes out of the water,
the contamination will turn in to cement whitin some days. That can be very difficult to remove.

[Cheechako]

If the boat sat a lot, tiny barnacles grow inside the bearing on the shaft. When you start up, the barnacles tear up the bearing to some extent. Maybe you have these in there?

[dsharp]

More than likely the cutlass bearing is dry or they don"t have the boat blocked sufficiently allowing the hull to sag slightly. Most glass hulls have enough material in the hull to prevent sagging. I'd bet on a dry bearing.

[skipmac]

Originally Posted by alangoose

The boat has now been out of the water for the whole summer so I will be testing again in a few weeks.

Alan

HI Alan,

If the boat has been sitting for weeks out of the water the problem could be misalignment. I restored an old boat and it sat out of the water for a few years and the hull shape changed a lot. I had to do a complete realignment when I finally relaunched. Even after the boat was back in the water it needs to sit a few weeks before it resumes the proper shape.

[Suijin]

Originally Posted by skipmac

HI Alan,

If the boat has been sitting for weeks out of the water the problem could be misalignment. I restored an old boat and it sat out of the water for a few years and the hull shape changed a lot. I had to do a complete realignment when I finally relaunched. Even after the boat was back in the water it needs to sit a few weeks before it resumes the proper shape.

This is an excellent point. It's why mechanics after shaft work perform final alignment back in the water after the boat has sat for a a few days.

[alangoose]

Skipjack:

Thanks for the response.

As I said in my original post, the boat had just been hauled after a winter of normal cruising without incident; my shaft resistance to turning occurred a few days after this hauling. I will be rechecking when I return to the boat in the next few weeks.

Alan

[boatbod]

Replace the cutlass.

I've seen this happen multiple times - once with 2.5" shafts! Not sure what caused it, but basically the rubber swells and jams the shaft. Can be a serious pita to get the shaft out...

[alangoose]

boatbode

Thanks for the reply. Your response covers what I hoped to avoid when I return to the boat, but I suspected as much!! Wishful thinking never does really work.

Alan

[boatbod]

Originally Posted by alangoose

boatbode

Thanks for the reply. Your response covers what I hoped to avoid when I return to the boat, but I suspected as much!! Wishful thinking never does really work.

Alan

You can try spraying down the insides of the rubber bearing with soapy water to see if it just needs lubrication, but usually replacement is the best option.