So today I started to get a really loud rumbling noise with vibration, feels and sounds like it's coming from the gearbox area, it's only present when I reach 15mph or if put it in low then it's present as soon as I move and louder than in high.
Problem is I'm in Cornwall with limited tools and home is 300 miles away, so my 1st question is any idea what the problem is and 2nd anyone know of a good mechanic in Hayle?
Thanks.

Hi, Make sure the prop shaft uj's are ok first. Sounds rotational speed related.
Griff

Or the rubber donut