Overheating drive shaft

[melons]

Am ever hopeful someone out there might have an idea...
Whilst crossing the Atlantic, we were 'lucky' enough to pick up a 15mtr fishing net. Once the lively seas had calmed a bit, the net was removed (to be later deposited in a Barbadian bin). A few days later we encountered the doldrums and so put the engine on. After about an hour, thought that we'd just check that all was well, to discover the shaft was burning hot, and so engine off. We have a shaft seal which, when relaunched 6 wks ago we had squeezed through the sea water to lubricate. On checking this, the water within was also burning hot. Since being in Barbados, we have checked the prop, the water inlets for the shaft seal appear/feel clear, our shaft is actually enclosed in a skeg, no sea water is leaking in anywhere and so at a loss as to why our shaft is heating to this extreme. Any thoughts would be gratefully received.

 

[tillergirl]

Some bits of poly wrapped around the shaft at the outboard end and binding on the cutlass?

 

[stevebirch2002]

Perhaps bent shaft and binding against any bearings you may have (Stern bearing, sterngland bearing etc). Happened to me on a Vega and turned out the new sterngland white-metal bearings were a tad tight!

 

[webcraft]

Are you sure it didn't do this before you picked up the net? Is the whole shaft getting hot, or just around the seal?

We have a Volvo shaft seal and the shaft is always hot near it. It is not burning but too hot to hold your hand on for more than a few seconds.

We worried for ages, but with 250 hours on it and some long runs of more than 12 hours continuius at cruising revs with no problems at all we have decided to mostly ignore it. It all comes down to how hot is hot - how hot does it need to get to actually damage the rubber of the shaft seal? (Because you certainly aren't going to get it hot enough to damage the actual propshaft in any way!)

- Nick

 

[Richard10002]

I overhauled my stern gland for the first time ever in Decenber, (sounds quite rude when I read it back <g>), tightening it until I got 1 drip every 10 seconds or so. The drips of water coming through with the engine running were hot enough to steam a bit, but I am guessing that if it is coming through, the shaft must be lubricated.

Have you investigated it previously and found it ran much cooler, or is this the first time you have checked "in anger" because of the problem. might be running at the right temp. I think someone suggested the gland wouldn feel like a hot cup of tea?

Cheers

Richard