?Cutlass Bearing Problem?

[Jerry]

In getting my CD30 ready to launch after a winter on the hard, I found that my prop was at first a little tough to rotate by hand. Turning it back and forth freed it up but it is still a little stiff. I also noticed that 3 small pieces of rubber or similar material were working their way along the shaft, coming out of the area of the cutlass bearing housing. There is no up/down or side to side play in the shaft to indicate a worn bearing but the bearing appears to be breaking up -- I don't know what else would account for the rubber material coming out of the bearing housing.

Questions: (1) Is it normal for the prop shaft to be hard to turn over by hand (with the transmission in neutral of course)? (2) Assuming that the cutlass bearing is the source of the rubber pieces, but considering the lack of play in the shaft, do the rubber pieces suggest a cutlass bearing failure is imminent? (3) If I don't replace the bearing right away and it does fail during the season, can I presume the stuffing box will prevent flooding the boat?

Due to the shortness of my sailing season I would prefer to delay repairing the cutlass bearing until fall layup, but not at the risk of losing the boat. Any comments would be appreciated.

[Steve Alarcon]

In getting my CD30 ready to launch after a winter on the hard, I found that my prop was at first a little tough to rotate by hand. Turning it back and forth freed it up but it is still a little stiff. I also noticed that 3 small pieces of rubber or similar material were working their way along the shaft, coming out of the area of the cutlass bearing housing. There is no up/down or side to side play in the shaft to indicate a worn bearing but the bearing appears to be breaking up -- I don't know what else would account for the rubber material coming out of the bearing housing.


Questions: (1) Is it normal for the prop shaft to be hard to turn over by hand (with the transmission in neutral of course)? (2) Assuming that the cutlass bearing is the source of the rubber pieces, but considering the lack of play in the shaft, do the rubber pieces suggest a cutlass bearing failure is imminent? (3) If I don't replace the bearing right away and it does fail during the season, can I presume the stuffing box will prevent flooding the boat?

Due to the shortness of my sailing season I would prefer to delay repairing the cutlass bearing until fall layup, but not at the risk of losing the boat. Any comments would be appreciated.

Jerry,
The difficulty in turning the shaft is caused by the friction in the cutlass bearing. The cutlass normally uses sea water to lubricate itself. It should be a bit stiff, but not impossible to turn. As to the rubber particles, it sounds like the "bearing" surface of the cutlass is degrading and this could be an expensive problem. If the rubber totally disintegrates, the shaft could ride on the metal part of the cutlass, requiring replacing the main shaft! If the bearing inner surface does totally go away the stuffing box "should" contain the inrush of water, but it is hard to anticipate the effect of the increased vibration of the main shaft on the stuffing box. My advice is to replace the cutlass bearing now. I think the peace of mind is worth it!

Steve Alarcon
CD30 Temerity
Seattle



alrcon@internetmci.com

[Tom Coons]

In getting my CD30 ready to launch after a winter on the hard, I found that my prop was at first a little tough to rotate by hand. Turning it back and forth freed it up but it is still a little stiff. I also noticed that 3 small pieces of rubber or similar material were working their way along the shaft, coming out of the area of the cutlass bearing housing. There is no up/down or side to side play in the shaft to indicate a worn bearing but the bearing appears to be breaking up -- I don't know what else would account for the rubber material coming out of the bearing housing.

Questions: (1) Is it normal for the prop shaft to be hard to turn over by hand (with the transmission in neutral of course)? (2) Assuming that the cutlass bearing is the source of the rubber pieces, but considering the lack of play in the shaft, do the rubber pieces suggest a cutlass bearing failure is imminent? (3) If I don't replace the bearing right away and it does fail during the season, can I presume the stuffing box will prevent flooding the boat?

Due to the shortness of my sailing season I would prefer to delay repairing the cutlass bearing until fall layup, but not at the risk of losing the boat. Any comments would be appreciated.

Jerry,
The difficulty in turning the shaft is caused by the friction in the cutlass bearing. The cutlass normally uses sea water to lubricate itself. It should be a bit stiff, but not impossible to turn. As to the rubber particles, it sounds like the "bearing" surface of the cutlass is degrading and this could be an expensive problem. If the rubber totally disintegrates, the shaft could ride on the metal part of the cutlass, requiring replacing the main shaft! If the bearing inner surface does totally go away the stuffing box "should" contain the inrush of water, but it is hard to anticipate the effect of the increased vibration of the main shaft on the stuffing box. My advice is to replace the cutlass bearing now. I think the peace of mind is worth it!

Steve Alarcon
CD30 Temerity
Seattle

I agree with everything Steve said, however one further considration would be how much do you run the engine in a season? If not too much you can probably get away with it. Since you say there isn't any play in it the deterioration probably isn't too advanced so it will probably last through moderate use. (There's a lot of probablys in there) Water is always going past the cutlass bearing and up against the stuffing box because the cutlass bearing needs water for lubircation.

One thing to ponder is why is the cutlass bearing breaking up like this? Usually they just wear down like brake shoes on your car until they get sloppy. Are you sure your engine is aligned perfectly? Are you sure there aren't any pits on your shaft that would eat the surface of the bearing? I've seen some really sloppy bearings (like 1/4" play) that didn't eat the rubber in the bearing I'd certainly be suspicious that something else than just wear is going on here. Whenever you do it, I'd recommend that you check everything to make sure it's just wear you're dealing with. I have a friend whose cutlass is over 20 years old and still has very little play. Mine is about 8 years old and has none.

You probably know that to replace the cutlass you have to pull the shaft. Getting the flange off the end of the shaft is sometimes a challenge that is discussed elsewhere here on the bulletin board and sometimes you have to cut the shaft in two and replace it. Have all that figured out and contingencies lined up if you're in a hurry to get back in the water and decide to do it at the beginning of the season here.

Tom Coons
CD 31 "Heiress"



TacCambria@thegrid.net

[Stephen]

One thing to ponder is why is the cutlass bearing breaking up like this? Usually they just wear down like brake shoes on your car until they get sloppy. Are you sure your engine is aligned perfectly? Are you sure there aren't any pits on your shaft that would eat the surface of the bearing? I've seen some really sloppy bearings (like 1/4" play) that didn't eat the rubber in the bearing I'd certainly be suspicious that something else than just wear is going on here.

I agree with Tom. Sounds fishy. Regarding alignment, keep in mind that it changes in the water vs. out of the water. Also, when out of the water almost all of the boat's weight should be on the keel blocks; the stands are just supposed to keep it upright. If one or more of your stands are cranked up too hard, or misplaced, it could distort the shape of your hull. Then, if you run your engine, without water to lubricate the cutless bearing, it could cause unusual wear on the rubber surface of the bearing.

Still, it seems strange that you would see bits of rubber. It sounds to me like something unusual is deteriorating the bearing, either something on your shaft or some chemical like acetone.

I replaced my own bearing on my 22D. With the help of Marine Diesel Engines by Nigel Calder I was able to do the job, though it took a while. I imagine an experienced repairperson could do the job pretty quickly.

BTW, I ended up pulling my engine to get the shaft out. It wasn't as bad as it sounds. On the Yanmar 1GM most of the wiring is in harnesses with detachment clips near the engine; all of the relevant hoses are attached with hose clamps. And, although my back paid for it for a couple of days, I was able to lift the engine off its feet and a few feet back into the cabin (I used some planks for leverage). Then, after pulling the prop, the shaft came right through.

The advantage to this method is that it makes it real easy to get at the cutless bearing, stuffing box, and surrounding area. I was able to clean out a part of the boat I'm sure went untouched since the engine was installed. Since I had the opportunity I replaced the stuffing box flexible hose and, of course, the flax. I also replaced the fuel hoses and water intake hose, which were on the surveyor's list of things to do last year when I bought the boat.

I don't know how much bigger your diesel is than mine, but don't rule out pulling the engine back out of the way to make your work easier. Ideally, you are short and strong, or else have short and strong friends.

Best,
Stephen



sailing@star.net

[Jerry]

In getting my CD30 ready to launch after a winter on the hard, I found that my prop was at first a little tough to rotate by hand. Turning it back and forth freed it up but it is still a little stiff. I also noticed that 3 small pieces of rubber or similar material were working their way along the shaft, coming out of the area of the cutlass bearing housing. There is no up/down or side to side play in the shaft to indicate a worn bearing but the bearing appears to be breaking up -- I don't know what else would account for the rubber material coming out of the bearing housing.

Questions: (1) Is it normal for the prop shaft to be hard to turn over by hand (with the transmission in neutral of course)? (2) Assuming that the cutlass bearing is the source of the rubber pieces, but considering the lack of play in the shaft, do the rubber pieces suggest a cutlass bearing failure is imminent? (3) If I don't replace the bearing right away and it does fail during the season, can I presume the stuffing box will prevent flooding the boat?

Due to the shortness of my sailing season I would prefer to delay repairing the cutlass bearing until fall layup, but not at the risk of losing the boat. Any comments would be appreciated.

Thanks to all for your comments, you convinced me to replace the bearing now rather than later. Being somewhat mechanically challanged and, frankly, a little scared-off by other postings to this board describing this task, I called in my friendly mechanic. One hour and $100 later, I have a new cutlass bearing.

Surprisingly, at least to me, the job required no motor removal, no shaft removal, no stuffing box removal, no nothing inside the boat except for the removal of a single nut. On the CD30, at least my '84 model, the whole job is done outside the boat. The mechanic pulled the prop, removed 1 screw and 1 bolt holding on the bearing housing on the outside of the keel and pried the housing off the shaft. With the bearing housing off the boat it was a simple matter to remove and replace the bearing.

As far as the reason for the cutlass bearing failure, the mechanic attributed it to old age -- the bearing was the original on this 14 year old boat.

Again, thanks for your help.