Replacing cutlass bearings?

  • Thread starter Thread starter RM
  • Start date Start date
R

RM

Member
Joined
Jan 1, 2000
RO Number
468
Messages
325
How do you know when these need to be replaced? Boat is an '88 and don't know if they ever have been replaced. Shafts seem tight but the bearings appear dry rotted to me. The starboard shaft squeals badly when turned by hand (out of water) port does not.

How big a project is this?
 
I've never seen them "dry rot" they always look "dry". They use the water as lube so squealing out of the water is not a big deal, most of them do. If the shaft have little or no side play, they are still good, bad ones will have seeable side play. You need a puller, there are two kinds, one requires shaft removal the other one doesn't. You also have to find and remove the set screws, likely have to drill them out and rethread, which makes shaft removal almost a must, but without the bearing sleave in there, there might be room to get the tap in.
 
RM, also look at both end of bearing for wear characteristics. Look to see if shaft is running down center of bearing. If you see a thinner wall on forward side and a corresponding thin side on aft part; you're out of alignment top to bottom or right to left.
 
When you have the boat out of the water... See if you have any play in the shaft by lifting the shaft after the cutlass bearing. If yes then they need to be changed. Not a lot of fun but necessary.
 
Repacing the cutlass bearing is no big deal and can easily be done without a puller provided you can remove the shafts.

First pull shafts, then remove set screws on sides of strut --usually 4 of them holding bearing. Next, using a hack saw blade inserted into the bearing and reversed--teeth facing inwards, carefully cut the bearing lengthwise--carefully cut only the bearing, not the strut. Once done the bearing will easily tap out. Note I had to cut bearing in 2 placed about 1 cm apart and peel the 1 cm section out.

Clean strut bore and press in new bearing using a large threaded rod (I used 3/4 inch) with large washers to pull in bearing.

Process is time consuming but quite easy. It took me about 6 hours total time. Actually most difficult part was raligning the shafts.
 
There are devices available that will allow removal without removing shafts. Many yards have hydraulic devices to do this. Obviously, prop has to be removed which ever way you go.
 
Hey BJ if you read anything, we told him that, you have the right name, BJ.
 
Yo Jim, sit on it !! I have seen so many responses repeated you can't count that high; I can but I doubt you can. Get a life.
 
If you can't move the shaft up and down your ok. If it squeals when it's dry this is good as it indicates no clearance.

It takes a long time to wear out a cutlass bearing unless you run in very dirty(sandy) water.

Even a little bit of slop doesn't hurt anything unless you get a significant, high frequency vibration, that goes away, when you back off the RPMs.

The ends that are visible can look dry and rough, but generally speaking the interior is normally in good shape if you have minimal/no slop.
 
Being an easy or a difficult job is the luck of the draw. I have done 3 replacements on 3 boats. 2 of them were full keeled boats & the third had a strut.

Having a strut & a removal tool is easy. Full keeled boats with the prop up close to the end of the keel is another matter. One of them required a great deal of 'persuasion' using various methods & language. The other came out easily after the whole assembly which holds the bearing was removed (2 bolts).

A little trick that nobody has mentioned so far is how to make installation easier. Warm the strut/holder. Makes it swell up. Chill the bearing in ice water. Makes it shrink. With a little lube or dishwashing liquid on the surface, slide it right in.

Done right & with a balanced prop & well aligned engine, cutless bearings should last thousands of hours of engine time.
 
Does age of the bearing in of itself cause them to breakdown and need replacing?
Greg
 
Greg, I don't think so. Mine are original on my '93, 37C. I check every spring & fall & surprisingly there is no play. Even tho I'm a firm believer in, "If it's not broken, don't fix it"........If I had to remove shaft for one reason or another I would probably replace just because of age. They are cheap enuff for preventive maintenance.
 
Thanks Bob. I had to replace stbd strut last year and of course got a new bearing on that side. The dealer said we "might as well replace the bearing on the other side". I didn't let him do that as Thr port side bearing looked ok and I had no play in the shaft.
Greg
 
My boat had 17 years before they were changed... There was a vibration while underway, so I stopped and dropped the hook,I dove down to see if I picked up some Debris in the wheels, they were clean, I checked the struts and cutlass bearings, the Port shaft was loose. I then ran her slow to a DIY yard in Daytona FL. While up on the hard I decided to have both cutlass bearings done. One less thing to worry about while I was cruising Coast wise. Ya got to do what ya gotta do.
 
Veebyes has some good points, one other spin on the ice suggestion, put them in the freezer overnight and take them out just prior to install.
 
You must log in or register to reply here.
Back
Top