Stern Tube Grease

[Porthandbuoy]

I pulled the propshaft and dismantled ladybird stern gear to repair a small, persistent leak from around the stern tube. I've discovered the stern tube has an inboard and an outboard white metal bearing, not a composite or rubber cutless bearing as I initially thought (though the absence of any cooling/lubricating water inlets should have made me think again).

The whole arrangement is unlike anything in Vyv Cox's website. Yanmar 1GM10 - flexible coupling - bronze stern gland c/w conventional stuffing box and white metal bearing bolted to deadwood - screwed to 8" stern tube - outboard white metal bearing screwed onto stern tube and bolted to deadwood. (I say deadwood even though it's GRP). It's all pretty inflexible as you can imagine, apart from the coupling.

The white metal bearing are in good nick; they slide and rotate smoothly on the shaft with no play. The leak from around the stern tube started after a rope wrapped itself around the prop and damn nearly kicked the Yanmar off its mounts.

I'm about to put it all back together and am wondering if there is a specific grease I should use in the stern tube greaser. Lithium, Molybdenum, PTFE?

 

[VicS]

I pulled the propshaft and dismantled ladybird stern gear to repair a small, persistent leak from around the stern tube. I've discovered the stern tube has an inboard and an outboard white metal bearing, not a composite or rubber cutless bearing as I initially thought (though the absence of any cooling/lubricating water inlets should have made me think again).

The whole arrangement is unlike anything in Vyv Cox's website. Yanmar 1GM10 - flexible coupling - bronze stern gland c/w conventional stuffing box and white metal bearing bolted to deadwood - screwed to 8" stern tube - outboard white metal bearing screwed onto stern tube and bolted to deadwood. (I say deadwood even though it's GRP). It's all pretty inflexible as you can imagine, apart from the coupling.

The white metal bearing are in good nick; they slide and rotate smoothly on the shaft with no play. The leak from around the stern tube started after a rope wrapped itself around the prop and damn nearly kicked the Yanmar off its mounts.

I'm about to put it all back together and am wondering if there is a specific grease I should use in the stern tube greaser. Lithium, Molybdenum, PTFE?

Ramonol Advanced https://www.gruebb.com/controlpanel/shoppics/pdfs/GruebbRamonolAdvancedTDS2016pdf.pdf

The ordinary Ramonol White grease will probably wash away too quickly, but read the tech specs.

Its expensive but available from the usual swindleries at around £18 for 500g

 

[vyv_cox]

Your arrangement sounds very similar to those shown in http://coxeng.co.uk/stern-gear/ one of which, the bottom one, is my motorsailer. In my case the bearing was very worn and I replaced it with Vesconite.

 

[Porthandbuoy]

Your arrangement sounds very similar to those shown in http://coxeng.co.uk/stern-gear/ one of which, the bottom one, is my motorsailer. In my case the bearing was very worn and I replaced it with Vesconite.

You're right of course. Obviously I didn't scroll down far enough. As my white metal seems okay I'll leave it alone.

VicS: Thanks for the pointer to Ramonol. I'll give it a shot.

 

[Bodach na mara]

The arrangement sounds similar to the original arrangement on a Westerly Renown which I had with a Watermota engine. By the time I bought it, the outer white metal bearing had been replaced with a Cutless bearing that had involved boring out (off centre!) the white metal into the bronze of the housing and turning down the outer metal of the Cutless to an interference fit in the hole. When I came to renew the Cutless, it led to a chain of renewals and I ended up with a new shaft, stern tube and housing along with a standard Cutless bearing needing no machining now.

Regarding grease, I had a can of Castrol CL, which I used in the greaser for the inner gland and tube.