Stick it!!

[bizzard]

In many cases grease nipples were fitted to various things that didn't have very good seals to keep water or rain water out and one pumped grease in to force any water out ei '' old type car track rod ends and king pins for example, if the seals had been sound there would have been no need, today the seals are sound so no need to pump grease into them anymore. As long as your bilge water does not rise up to reach that bearing so not the need to pump grease in just to force water out.  Boat trailer wheels invariably have grease nipples on the hubs mainly to pump grease in to force any water out if the trailer had been dunked, launching a boat or retrieving it.

Edited April 19, 2020 by bizzard

[cuthound]

 

2 hours ago, Opener said:

OK - what is WRONG with you guys!!!  Everyone is coming up with sensible, practical and proper engineering solutions.  But, what about MY stupid idea as a temporary fix?  Clean up/degrease area, roughen and build up a shoulder around the nipple - will it hold and what brand should I use?

I take the point about there probably being enough lubricant in the bearing to last but, if so, why is there a nipple on it?  Is that just to confuse amateurs like me?

Thanks Bee - the nipple actually came out clean - the only good point about the whole fiasco.

OK Tracy - if i'm not going to drill through the raceway, is there any point in drilling in a new location at all?  Do you reckon there will be an opening at the nipple gallery but only there?

I'd probably leave well alone, as widely suggested, but I do get a tortured metal-on-metal scream at certain revs under drive which I haven't tracked down yet - a bit dodgy sailing alone with the cruiser deck boards open - may have to stick the crew down there with the hatches closed to do a definitive check.

Ain't boating fun!

 

When you say the nipple came out clean, do you mean the thread in the bearing it was screwed into stripped, so the nipple is undamaged?

 

If this is the case, get a helicoil to match the thread on the grease nipple, tap the hole in the baring to the appropriate size, insert the helicoil and then screw the grease nipple back in.

 

It is simple and unlike your temporsy fix is not a bodge. 

 

This video shows you how to do it.

 

 

If you put a blob of grease on the tap, it will catch the swarf and tang so that it comes out when the tap is withdrawn thus preventing it from getting into your bearing.

Edited April 19, 2020 by cuthound
To remove a duplicate post and clarification

[ditchcrawler]

2 hours ago, Opener said:

OK - what is WRONG with you guys!!!  Everyone is coming up with sensible, practical and proper engineering solutions.  But, what about MY stupid idea as a temporary fix?  Clean up/degrease area, roughen and build up a shoulder around the nipple - will it hold and what brand should I use?

I take the point about there probably being enough lubricant in the bearing to last but, if so, why is there a nipple on it?  Is that just to confuse amateurs like me?

Thanks Bee - the nipple actually came out clean - the only good point about the whole fiasco.

OK Tracy - if i'm not going to drill through the raceway, is there any point in drilling in a new location at all?  Do you reckon there will be an opening at the nipple gallery but only there?

I'd probably leave well alone, as widely suggested, but I do get a tortured metal-on-metal scream at certain revs under drive which I haven't tracked down yet - a bit dodgy sailing alone with the cruiser deck boards open - may have to stick the crew down there with the hatches closed to do a definitive check.

Ain't boating fun!

There will not be an opening directly below that nipple through the outer bearing anyway, there may be a gallery behind it.

 

[smiler]

3 hours ago, Opener said:

OK - what is WRONG with you guys!!!  Everyone is coming up with sensible, practical and proper engineering solutions.  But, what about MY stupid idea as a temporary fix?  Clean up/degrease area, roughen and build up a shoulder around the nipple - will it hold and what brand should I use?

I take the point about there probably being enough lubricant in the bearing to last but, if so, why is there a nipple on it?  Is that just to confuse amateurs like me?

Thanks Bee - the nipple actually came out clean - the only good point about the whole fiasco.

OK Tracy - if i'm not going to drill through the raceway, is there any point in drilling in a new location at all?  Do you reckon there will be an opening at the nipple gallery but only there?

I'd probably leave well alone, as widely suggested, but I do get a tortured metal-on-metal scream at certain revs under drive which I haven't tracked down yet - a bit dodgy sailing alone with the cruiser deck boards open - may have to stick the crew down there with the hatches closed to do a definitive check.

Ain't boating fun!

You're bodge idea may work but I would use liquid metal (Belzona) rather than the repair putty type materials.

I would first clear out as much grease from the nipple hole as possible and fill the hole with thickish oil (engine oil would be ok). Leave overnight to creep through into the bearing just to get some lube in there.

Next degrease the hole and nipple with brake cleaner or similar, smear a little Belzona on the nipple threads and screw it in by hand. After this has hardened then build up around to strengthen it.

TBH - after buying Belzona and degreaser you would maybe cheaper buying a new bearing.

If it is screeching now, as you say you think it is, it's maybe time for a new bearing anyway.

[Ray T]

Just a thought re the OP. Is your bearing a thrust bearing or just support for the propshaft?

The set up on our boat is a Plummer Block, also called a Pillow block. https://en.wikipedia.org/wiki/Pillow_block_bearing

 

The inner collar of the block has grub screws which when screwed down grip the prop shaft in little indents and transmit some of the forward thrust to the bulkhead it is bolted to.

This relieves the engine mounts of some pressure. 

 

Even though the bearing is regularly greased in my experience this block has needed renewing approx every 5 years. 

The outer race has two grooves machined in it to help the distribution of lubricant. 

If you look at the pictures the bearing has almost been worn down to the level of the grooves. Old bearing taken out of its housing, new bearing in housing.

 

If the screeching noise is coming from the block I would, for peace of mind, replace the whole bearing.

 

 

 

Edited April 19, 2020 by Ray T

[Opener]

On 19/04/2020 at 15:24, Ray T said:

Just a thought re the OP. Is your bearing a thrust bearing or just support for the propshaft?

The set up on our boat is a Plummer Block, also called a Pillow block. https://en.wikipedia.org/wiki/Pillow_block_bearing

Fairly certain, from what you say, that I simply have a different design of the Pillow Block you have.  Sounds like I need to examine mine in more detail to work out what moves and what does not. 

Where did you source your new bearing?

[Ray T]

40 minutes ago, Opener said:

Fairly certain, from what you say, that I simply have a different design of the Pillow Block you have.  Sounds like I need to examine mine in more detail to work out what moves and what does not. 

Where did you source your new bearing?

I got my new bearing from RLWP of this parish. Midland Chandlers plus others sell them too.

Or try the inter web.

 

https://www.midlandchandlers.co.uk/search?query=bearing

 

https://simplybearings.co.uk/shop/Bearings-Housings-&-Inserts/c3_6316/index.html

 

 

Edited April 20, 2020 by Ray T

[bizzard]

The best thrust block type are the ones with twin Timken tapered roller bearings. Dodge Fenner  . BRT bearings I found are the cheapest, if you have a trade order.

[David Mack]

On 19/04/2020 at 15:24, Ray T said:

Just a thought re the OP. Is your bearing a thrust bearing or just support for the propshaft?

The set up on our boat is a Plummer Block, also called a Pillow block. https://en.wikipedia.org/wiki/Pillow_block_bearing

 

The inner collar of the block has grub screws which when screwed down grip the prop shaft in little indents and transmit some of the forward thrust to the bulkhead it is bolted to.

This relieves the engine mounts of some pressure. 

 

Even though the bearing is regularly greased in my experience this block has needed renewing approx every 5 years. 

The outer race has two grooves machined in it to help the distribution of lubricant. 

If you look at the pictures the bearing has almost been worn down to the level of the grooves. Old bearing taken out of its housing, new bearing in housing.

 

If the screeching noise is coming from the block I would, for peace of mind, replace the whole bearing.

 

 

 

If the outside of the outer race has worn down to that extent, then it must be constantly moving within the plummer block. Which suggests either your prop shaft is bent or something is seriously flexing.

[bizzard]

Proper thrust block. The Dodge Fenner type, twin Timken taper roller bearings. My old Harborough Marine ex hire boat had one, and was original 20 odd years old to my knowledge.

[Ray T]

34 minutes ago, David Mack said:

If the outside of the outer race has worn down to that extent, then it must be constantly moving within the plummer block. Which suggests either your prop shaft is bent or something is seriously flexing.

Had the prop shaft checked in the past, it is as straight as a die. The outer casing has never been replaced and may be worn.

Edited April 21, 2020 by Ray T

[Keeping Up]

29 minutes ago, David Mack said:

If the outside of the outer race has worn down to that extent, then it must be constantly moving within the plummer block. Which suggests either your prop shaft is bent or something is seriously flexing.

What stops it from moving within the block? My engine moves back & forth by about 5mm, as I engage forward/reverse, especially if anything gets onto the prop. My engineer (Jono at UCC) advised me to leave the grub screws loose so the shaft could slide freely, with just a hint of tightening to ensure that it is the bearing which rotates rather than the shaft rotating in the sleeve. Surprisingly the screws don't need constant readjustment to achieve this.

[Tony Brooks]

11 minutes ago, Keeping Up said:

What stops it from moving within the block? My engine moves back & forth by about 5mm, as I engage forward/reverse, especially if anything gets onto the prop. My engineer (Jono at UCC) advised me to leave the grub screws loose so the shaft could slide freely, with just a hint of tightening to ensure that it is the bearing which rotates rather than the shaft rotating in the sleeve. Surprisingly the screws don't need constant readjustment to achieve this.

Much depends upon the exact design/specification of the block in use as Biz showed a proper thrust block is larger than the OP's and is very much heavier. It probably has a pair of taper roller bearings or angular contact ball bearings in it to both support the shaft and transfer the prop thrust to the hull. I think both yours and the OP's blocks are just to support the shaft and probably have ordinary ball bearings in the or deep groove ball bearings if you are lucky. These are not anywhere near as good at transferring prop thrust so agree with Jonno.

 

If I had the OP's boat and probably yours I would be fitting a proper thrust bearing and taking exceptional care over the alignment. The type of support shown is in my view ideal for supporting long prop shafts as long as the first support is a thrust bearing like Biz showed.

 

Better still with a flexibly mounted engine would be to fit a proper flexible coupling like an Aquadrive, Python drive or long Centafex. A thrust bearing is not required with a rigidly mounted engine.

Edited April 21, 2020 by Tony Brooks

[bizzard]

I'm not keen on rubber mounted engines unless as TB mentioned they have a double UJ type connection of some kind like the Aquadrive and thrust block. If there's no room for one I'd solid mount the engine, align it accurately and put up with the extra bit of vibration, much more reliable and no keep messing about with busted mounts and alignment.

[bizzard]

47 minutes ago, Keeping Up said:

What stops it from moving within the block? My engine moves back & forth by about 5mm, as I engage forward/reverse, especially if anything gets onto the prop. My engineer (Jono at UCC) advised me to leave the grub screws loose so the shaft could slide freely, with just a hint of tightening to ensure that it is the bearing which rotates rather than the shaft rotating in the sleeve. Surprisingly the screws don't need constant readjustment to achieve this.

The screws would scrape grooves in the shaft with the fore and aft movement and keep the inner bearing track from rotating with the shaft. Not a nice fix, but I suppose not much alternative if there's no room for a proper double UJ Aquadrive. This is the trouble with more modern boats everyone clamours for more and more cabin space with the engine and transmission stuffed right up the back as possible and sacrifice sufficient engine space with a proper marine inatallation.

Edited April 21, 2020 by bizzard

[Opener]

On 19/04/2020 at 15:24, Ray T said:

Just a thought re the OP. Is your bearing a thrust bearing or just support for the propshaft?

The set up on our boat is a Plummer Block, also called a Pillow block. https://en.wikipedia.org/wiki/Pillow_block_bearing

Fairly certain, from what you say, that I simply have a different design of the Pillow Block you have.  Sounds like I need to examine mine in more detail to work out what moves and what does not. 

Where did you source your new bearing?

[Opener]

OK - laugh at OP time. I've never sat in the (cruiser stern) engine bay while the boat is under way so don't know what turns and what moves/stays still. But are we saying that, in my original post picture, the silver bit sticking out of the bearing housing is fixed to the prop shaft (??grub screws have been suggested) and a second, larger diameter component remains static in the blue housing with bearings between the two.

In retrospect that now makes more sense to me so that the forward end of the shaft is supported in a proper bearing rather than just a 'sleeve' and any vertical stress within the tail of the gearbox is avoided/limited.

[Tony Brooks]

49 minutes ago, Opener said:

OK - laugh at OP time. I've never sat in the (cruiser stern) engine bay while the boat is under way so don't know what turns and what moves/stays still. But are we saying that, in my original post picture, the silver bit sticking out of the bearing housing is fixed to the prop shaft (??grub screws have been suggested) and a second, larger diameter component remains static in the blue housing with bearings between the two.

In retrospect that now makes more sense to me so that the forward end of the shaft is supported in a proper bearing rather than just a 'sleeve' and any vertical stress within the tail of the gearbox is avoided/limited.

Yes, but with that not very flexible R&D so called flexible coupling any dropping of the engine on its mounts will load the bearing. Personally I can't see the point of the bearing on such a short length of unsupported shaft. It would be different if the "flexible" coupling allowed for radial misalignment but yours dos not in any meaningful sense.

 

 

Edited April 22, 2020 by Tony Brooks