Replacing a cutless bearing.

[ash2020]

Hi all.

I finally managed to get my prop off by making up a heavy duty puller and applying lots of heat. Last time I tried, I gave up. So I am now going to fit a shave type "Quickutter" rope cutter and replace the cutless bearing while I'm at it. I've taken the stern tube off as you see, it appears to be bronze and I think the old bearing has a brass sleeve. It's 3/4 shaft size so pretty small. I can get a new 3/4 x 1 1/4 x 3" bearing. Question is, should I just attempt to drift the old one out cold and press the new one in cold? Would you apply some studlock or similar with the new one? How difficult is it going to be? It's probably been in for at least 10-15 years.

 

[srm]

Lots of discussions on cutless bearings over the years. Have you used the search facility?

 

[ash2020]

Lots of discussions on cutless bearings over the years. Have you used the search facility?

Thanks. I will have a look.

 

[LadyInBed]

Put the assembly in a vice, put a hacksaw blade through the hole, connect the hacksaw blade to the hacksaw, saw till you are just about through the brass.
You then have choices:

• Saw till you are through.
• Chisel between brass and bearing case to bend the brass.
• Make another saw cut the width of the chisel blade away from the first cut then chisel out that section.

Drift out the brass bearing.

 

[Tranona]

Best to press it it out and the new one in. Once you have it out you can confirm the outside diameter before you order the new one. Check that there is not a grub screw in the side to lock it in before you press it out. If not it will be a press fit and needs nothing else to hold it in place. Alternatively if you are fitting a Quickcutter (are you sure that is a good choice for your tiny little shaft?) then send the housing to h4 and have a composite bearing fitted at the same time.

 

[ash2020]

Put the assembly in a vice, put a hacksaw blade through the hole, connect the hacksaw blade to the hacksaw, saw till you are just about through the brass.
You then have choices:

• Saw till you are through.
• Chisel between brass and bearing case to bend the brass.
• Make another saw cut the width of the chisel blade away from the first cut then chisel out that section.

Drift out the brass bearing.

Thanks for that. Unfortunately, on the other end (that you can't see) there is a 1" thread that screws onto the stern tube housing, as the brass bearing sleeve is 1 1/4" I couldn't saw the bearing without cutting into the thread.

 

[ash2020]

Best to press it it out and the new one in. Once you have it out you can confirm the outside diameter before you order the new one. Check that there is not a grub screw in the side to lock it in before you press it out. If not it will be a press fit and needs nothing else to hold it in place. Alternatively if you are fitting a Quickcutter (are you sure that is a good choice for your tiny little shaft?) then send the housing to h4 and have a composite bearing fitted at the same time.

Thanks. Yes, I really should confirm the diameter before ordering the new one, although I'm 99% certain it's an imperial 1 1/4".
I've spent ages talking to Neil at H4 and he seems to think it'll be OK. I'll be machining the composite spool and I'm going to make a notched sleeve in 316 stainless to fit over the bronze stern tube and give a much more solid mounting for the cutter. I've got as far as drawing it!
Their logic attracts me. If the rope is wrapped round and static to the prop, a knife type will not work. The only way a knife or scissor will work is if the rope is static relative to the P bracket. Also, I can't afford an Ambassador at £700. I can do this for around £400
Do you have experience of the Quickutter? I like the fact that the RNLI and the military use them.