Shaft Bearing

[Y88 5241 25]

Looking for a bit of help, we had the boat out (Y88) for  wash the other day and noticed a lot of slop in the rear shaft support as circled in red below. It appears a bit of old rubber or plastic bearing still inside but mostly gone. Any suggestions on what I would fit here to remove the slop and where to get it from? TIA as wanting to get this sorted reasonably quickly.

[Island Time 1,239]

It's called a cutlass bearing. Have to have the right size and tools to press out the old one and replace. Any marine engineering shop can do it

[Fish 0]

We made a tool to press out our cutless bearing with the shaft in place. Means we can do it between tides and don't need to remove the shaft, which involves removing the rudder, which becomes a substantial job.

 

Our tool works for a 1 1/4 " shaft, 1 3/4" bearing. I'd expect a Y88 to have a smaller shaft than that.

 

If your capable at DIY, its not hard to make a tool up, means you can change the bearing drying out on piles, as opposed to commercial haul out, disassembly of half the boat etc.

we used 2 x 1 inch threaded rod. Got two steel plates made up (by an engineering firm), and a bit of scaffold tube cut in half.

Both steel plates have holes for the threaded rod. One steel plate has a hole bigger than 1 3/4" for the bearing to fit through. This plates sits / pushes on the P bracket / strut. The other plate has a hole just bigger than the shaft (1 1/4"). The tube needs to be bigger than the shaft and smaller than the outside diameter of the bearing. Cut it in half so it can go over the shaft. We used velcro to hold it together over the shaft. One plate on the P bracket, wind the threaded rods so that the other plate pushes the tube. Tube pushes the bearing out as you wind the two threaded rods in evenly.

 

Helps if you have two people, just to get set up. Cost of the parts is probably cheaper than a lift and hold at any travel lift.

 

If anyone wants to borrow the gear for a 1 1/4 " x 1 3/4" bearing, pick up is in Whangaparaoa.

[Y88 5241 25]

Awesome thanks Fish, I’ll PM you as we do have a 1 1/4 shaft! Be great to be able to borrow the tools!

[Y88 5241 25]

We made a tool to press out our cutless bearing with the shaft in place. Means we can do it between tides and don't need to remove the shaft, which involves removing the rudder, which becomes a substantial job.

 

Our tool works for a 1 1/4 " shaft, 1 3/4" bearing. I'd expect a Y88 to have a smaller shaft than that.

 

If your capable at DIY, its not hard to make a tool up, means you can change the bearing drying out on piles, as opposed to commercial haul out, disassembly of half the boat etc.

we used 2 x 1 inch threaded rod. Got two steel plates made up (by an engineering firm), and a bit of scaffold tube cut in half.

Both steel plates have holes for the threaded rod. One steel plate has a hole bigger than 1 3/4" for the bearing to fit through. This plates sits / pushes on the P bracket / strut. The other plate has a hole just bigger than the shaft (1 1/4"). The tube needs to be bigger than the shaft and smaller than the outside diameter of the bearing. Cut it in half so it can go over the shaft. We used velcro to hold it together over the shaft. One plate on the P bracket, wind the threaded rods so that the other plate pushes the tube. Tube pushes the bearing out as you wind the two threaded rods in evenly.

 

Helps if you have two people, just to get set up. Cost of the parts is probably cheaper than a lift and hold at any travel lift.

 

If anyone wants to borrow the gear for a 1 1/4 " x 1 3/4" bearing, pick up is in Whangaparaoa.

Where did you get your bearings from?

[Fish 0]

There is a wide range of bearings available.

 

The classic bearing is a rubber bearing with a bronze casing - trade name 'Cutlass' is the 'original', but there are many other manufacturers.

You can also get 'modern' plastic / polymeric bearings, eg Thordon bearings from Henley's, or Visconite from Chatfields or a bunch of other suppliers.

The plastic style bearings are supposed to last longer. Its all a question of price, marketing and spec. The plastic ones I think have a greater thermal coefficient so they are easier to freeze fit (freeze them or use dry ice and slide them in while they have cold shrunk).

 

There are some cheapy options, a rubber bearing with a phenolic casing, we had one of those and it lasted about 5 minutes. We have a 'Cutlass' brand rubber bearing at the moment, seems OK. The bronze casing seems best for press fitting. We are trying out a Thordon bearing in our stern tube but have only just re-launched so have no track record yet.

 

Bearing in this size is around $200 give or take. Best just to google NZ suppliers and go from there.

[Crazyhorse 47]

Any chance of posting how the Thordon goes Fish? Would like to know. We went vesonite and a small amount of play after only about 80hrs so not sure we made the right decision. Time will tell.

[Guest 000]

Don't wish to hijack this thread, but..

On my canal boat, and all others that I have seen in Europe the shaft bearings are bronze. In the engine room there is a humungous installed grease gun type thing that holds about 3 litres of grease and is connected via rigid pipework to the shaft tube. On top of the grease gun there is a handwheel and you give it half a turn every 6 - 8 hours of running. This greases the bearings and also the stuffing box so the shaft tube is in effect totally filled with grease with the excess exuding out of the shaft tube at the prop end.

According to the surveyor who did the job on my boat these bronze bush systems have a very long service life.

I am not at all familiar with this arrangement,but seems to do the job ok.

[Fish 0]

We just pulled out the NZ equivalent, but while the casing is bronze the bearing is a white metal. Grease gun permanently attached to the packing gland, pumped every time we finished using the donk. Lubricates the bearing, keeps the packing gland packed with grease and the stern tube filled up and oozing out into the environment.

 

Other than the need for constant attention, the only problem was to renew the bearing required taking the whole damn thing out of the boat, which was a substantial job, mainly cause the packing gland had a rectangle flange that was hard up against the keelson, and needed to be unscrewed from the stern tube. Once the packing gland is out of the boat, a new white metal bearing can be poured in (hot), then machined to size. But to save the palava, and based on the adage of do it once do it right, I prized my wallet open for a maintenance free drip less shaft seal and a Thordon bearing that I can change without having to disassemble 3/4's of the boat.

 

And now I wont have to crawl down back past the engine and pump a grease gun every time we get back to the mooring. Also hoping for a dry bilge, but I'll see what happens on that front.

[waikiore 400]

If you have a Y88 it will be an 1" shaft and usually 1 1/4" OD cutless bearing (the most common size) available at most good chandlers or BLA on the shore or Lusty and Blundell. Unless its the one with the Honda civic engine -that may have a bigger shaft !