Volvo Penta Gearbox Whine

[Jimfish]

I have a 2012 VP d1-30F with a MS10A gearbox shaft drive on my Moody 336 'Escapade'.

When I engage forward gear there is a distinctive whine which is not present when in neutral (under any revs) and is present but less pronounced in reverse.

Can anyone offer some guidance on what the cause may be? I have had the boat for about 3 years now and honestly cant recall if the noise has always been there.

I am almost certain that the noise is not coming from the cutlass bearing. It is also not a singing prop - I have an excellent Darglow featehring prop and its not from the shaft seal.

With forward gear engaged the whine is right across the engine rev spectrum - ie it doesnt disappear between any range of revs.

The gearbox oil is clear and the gearbox doesnt get warm when running.

The engine has done about 500 hours.

All suggestions welcome.

Thanks Jim

 

[earlybird]

The only suggestion I can make is a noisy bearing on the output shaft This will be under end- thrust in forward and astern but not in neutral. A check might be to use a stick of wood as a "stethescope" to try to locate the position of the noise origin.
Bear in mind that, once noticed, a previously minor noise can become a bit intrusive so maybe was there all the time.

 

[TRUNDLETRUC]

We had a real problem with a feathering prop. It sounded like the sail drive bearings and they were changed at quite a cost but we still had the noise! Cutting a long and expensive story short we borrowed a different prop and that solved the problem. If you cannot feel any play in the bearings? I would change the prop and see if that makes any difference.

 

[pandos]

If you put it in neutral, engine off, and spin the shaft by hand do you get the noise... Maybe in the relative silence you might be able to discern the location ..