Vibration/shake in Astern - Dufour 40

[Ripster]

Marry Xmas all. I have recently acquired a 2007 Dufour 40. Very pleased with her overall, but one of the niggles is a shake that occurs when going astern at higher RPM . At lower revs it's fine, but starts to shake if you need higher revs. My suspicions are prop balance or perhaps damage to a blade? She is fine going forwards very smooth at all RPM. She has a sail drive with D2-55 Volvo and Volvo folding 3 blade prop. Anyone else had this with a Volvo folder or got any other suggestions?

 

[Caer Urfa]

Check the engine mounts

 

[Neeves]

Check the cleanliness of the prop.

Make sure all 3 prop blades open evenly and correctly.

If this was a permanent feature I would have expected it to be apparent during inspection and survey prior to sale/purchase. If these were conducted and correctly it sounds (feels) like something new which suggests nothing drastic. Might be a bit cold to make a quick swim.......

Jonathan

 

[ashtead]

I wonder if anything wrong with the Volvo folder ? I might have that checked out fairly soon as a first step . It seems to me you might need someone like Paul who posts on here other another private engineer to listen as it could be the sail drive maybe ? Don’t be tempted to use main Volvo dealers though unless deep pockets backed on my experience of some well known Solent based ones.

 

[RivalRedwing]

how often are you going astern at high rpm???

 

[Neeves]

how often are you going astern at high rpm???

Maybe this is a novel idea but I have to wonder if:

People might power set their anchor at high rpm

Jonathan

 

[jaypea]

Check the oil in the saildrive, not sure which unit you have on the D40 but some of them use ordinary engine oil........this was put into ours (in error) by a service engineer on our boat as he hadn’t checked the spec for our 120s which actually requires (expensive!) gear oil Everything worked fine in forward gear but sounded like a box of spanner’s in reverse........all okay once the oil was replaced.