es curioso que viendo foros en ingles lo que se recomienda es normalmente lo contrario, dejar el eje que gire libremente y que asi el barco va mas rapido.
Como ejemplo
http://jeanneau.proboards.com/thread...r-when-sailing del que destaco esto
I spoke about this to the engineering firm that maintains my Volvo MD2020 engine. They say a Yanmar and some Volvo engines have a cone-shaped clutch area that has a shallow screw thread running on the surface. They showed me one to explain.
The thread locks into a similar thread on the other half of the clutch. The reason it won't go out of gear without the engine running is that the lock must be 'unscrewed' by the engine torque. It is advised not to try and break the clutch action using the lever, as this may damage the surface.
Starting the engine with the prop in gear doesn't seem to be harmful as I thought. So indeed, if you have a Yanmar, leave the prop freewheeling under sail.
My own 2004 Volvo MD2020 has a plate clutch which will go out of gear without having to 'unscrew' like the Yanmar clutch. I can just move the lever to neutral without any counter pressure. This is the case with most of the later Volvo engines, but the older ones may have a different type clutch. If the clutch casing is grey, generally it is the later type. If it's painted white, it may be the early type which acts like the Yanmar.
http://i60.tinypic.com/hwzpmq.jpg
http://i62.tinypic.com/2gwan13.jpg
I am a Marine Engineer (but on very large ships) and I have had the same discussion on a number of occasions with people all around the world. My take on it is this.
When your prop shaft is turning, whilst sailing, all that turns within the gearbox is the ‘output shaft and the friction clutch pack – not the gearing. As the final drive is ‘free rotating’ and not transmitting power from the engine, the loads and stresses on the bearings are negligible. The shaft will rotate within 2 thrust (ball) bearings and 2 needle roller bearings. The clutch pack is immersed in the oil and will ‘throw’ oil around the inside gearbox casing sufficiently to lubricate these bearings.
My solutions is that I let the shaft rotate – have done on all the yachts I have owned and yet to have a problem as a result of ‘freewheeling’.
Martin Payne
August Sun’
Bahamas