Gibble bearing

FF said:

"So...given the history of failure of this bearing, I would investigate this further."


Best guess it was under water.

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Makes one question whether ball/roller type bearings(sealed? or not) should ever be used in a marine environment. They are very susceptible to rust.
Perhaps there is a reason for using babbit type bearings instead. Ref. post 19.
Len

Mine run about 85 degrees

Unless the bearing is hot to the touch it's probably fine. I wouldn't change it out unless you see the temperature trending up over time.

Some bearings run warm their whole life and last just as long as the identical one next to it running at half the temp. As a millwright, I've always looked for temp and vibration trends in bearings as the surest indication of imminent failure. Keep an eye on it and record the running temps for a few weeks. If it's rising swap it out.

Gibble Bearing

I also have a Sundowner Tug. The fitting you are talking about is a carrier bearing. I check for grease every 100 hours of use ( more frequently when I was getting used to it ). I keep a loaded grease gun aboard.

wdmckie said:

.... I keep a loaded grease gun aboard.

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Do you need a license for it? I have one too,steering gear,windlass,bow roller etc, have grease nipples/zerks.

122 degrees by itself isn't too high, but I'd be concerned over the cause. You might want to "listen" to the bearing. Fret corroding due to lack of lubrication or moisture in the bearing will create "Flats" on the balls and "holes" in the contact angle which will generate heat and give an audible rumble.

I'm assuming that your Tug is like ours with the 2 cutlass bearings, intermediate bearing and transmission flange. A miss alignment can be another cause of a "hot" bearing.

Our intermediate bearing was new last year and runs at about 100 degrees after 1 hour and holds steady.

Our WOT is 2,800 rpm with about 1,500 rpm max. at the shaft. However, we normally run in the 1,200 to 1,800 rpm (5 to 6 kt) range so this could effect our readings.

wdmckie said:

I also have a Sundowner Tug. The fitting you are talking about is a carrier bearing. I check for grease every 100 hours of use ( more frequently when I was getting used to it ). I keep a loaded grease gun aboard.

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Good choice of boat! Welcome aboard

You can also overfill the bearing with grease, also causes heat so take care not to fill that much or too often

jleonard said:

Put an automatic grease system on like this (McMaster Carr) and you won't have to worry about it.

I put one of these on my "ex" an old 34 Mainship as the fitting was hard to get to. I used a length of hydraulic hose to get it to a handy location.

I also had on of those go bad...it squeaked (when I went into reverse) and rumbled. If it's quiet don't worry about it.

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The grease fitting is for the grease between the pillow block and the outside of the cage of the bearing, for misalignment only, crooked shaft. The bearing itself is a sealed bearing.

sum-r-fun said:

The grease fitting is for the grease between the pillow block and the outside of the cage of the bearing, for misalignment only, crooked shaft. The bearing itself is a sealed bearing.

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I know this and....?