New to shafts - leave in/out of gear when moored?

[Biggles109]

Some basic advice please - I recently bought my first shaft drive boat, having had outdrives and an outboard on my previous two boats. All good so far, and enjoying miserly fuel consumption from a single Volvo D3 that still has a bit of oomph when needed.

My boat is kept on a swing mooring with up to around 4 knots of tide running against her. Obviously this causes the prop and shaft to rotate when moored, should I let it do this (and presumably wear the cutlass bearing eventually), or do I leave the boat moored in gear (and if so is forward or reverse less likely to cause damage elsewhere in the driveline?).

 

[PCUK]

If you have hydraulic gearboxes it will make no difference as being in gear won't lock the shafts. The clutches need oil pressure from running the engines to operate the gearbox oil pumps to engage the clutches. If you want to lock the shafts you will need a shaft brake or something wedged into the shaft coupling bolts. If you wedge the shaft you MUST remember to remove the wedge before starting!!! Finally some makes of gearbox shouldn't be run without the engines running as there is no oil pressure to keep them lubricated so you may need a shaft brake to save the gearboxes as well as the cutless bearings. Not something I've ever thought about before now. I'm sure others will have dfferent ideas.

 

[longjohnsilver]

Don't leave it in gear, can cause premature gearbox wear. I also have a mooring with lots of tide, we have rigged up a prop shaft break from twine, (or fishing line) so that if we forget it, the twine breaks without causing damage. Costs nothing, but very effective. And you soon get used to connecting it to the shaft at the end of the day, and taking it off again next time you take the boat out, maybe put a reminder note on the morse control lever.

 

[burgundyben]

Don't leave it in gear, can cause premature gearbox wear. I also have a mooring with lots of tide, we have rigged up a prop shaft break from twine, (or fishing line) so that if we forget it, the twine breaks without causing damage. Costs nothing, but very effective. And you soon get used to connecting it to the shaft at the end of the day, and taking it off again next time you take the boat out, maybe put a reminder note on the morse control lever.

V clever!

 

[Biggles109]

Thanks all - sound advice from here as always, appreciated..

 

[prv]

The boat next to ours suffered quite a serious fire, due to friction heat, when the owner forgot to disengage his shaft brake before starting the engine. So if you do go for a proper mechanical brake rather than Longjohnsilver's string, some sort of interlock or at worst an alarm seems like a good idea. I believe many US states require an interlock to prevent starting with the engine in gear, so although I'm not very familiar with typical motorboat systems, there may well be a suitable connection that can be used to prevent starting with the brake engaged.

Pete

 

[DavidJ]

Suffering a lot with barnacle build up on my outdrive props, I wonder if having a prop that rotates stops the little blighters from clinging on?

 

[superheat6k]

Suffering a lot with barnacle build up on my outdrive props, I wonder if having a prop that rotates stops the little blighters from clinging on?

Only if they are freewheeling almost at planing speed !

I tried a three part system from Seajet 'Triple Pack'. Lasted less than a month / 80 miles, so don't bother, a pot of lanolin will last as long and a lot less cost (as long as you don't bake it in your oven !).