There should be a stud/nut and possibly a bushing under that mastic on the bottom of the C-DRIVE. This stabilizes the C-DRIVE from any twisting due to thrust. Inspect it by removing the mastic. 

Hi all,

 

In the last few days I've noticed a strange, intermittent vibration that seems to be coming from my propeller.

 

We had the engine mounts and Vetus coupling rubber balls replaced in Le Marin a few months ago, and this vibration does not feel similar to the one from when those needed replacement (and the mounts and coupling still look and feel fine).  This vibration is almost unnoticeable in the cockpit, but you can feel it when trying to sleep in the aft cabin, particularly in your legs (i.e. far aft).  It is rather intermittent, only lasting a few "thumps" at a time.  It seems to correlate when the boat is strongly rolling from one side to the other and often goes away when we're at a constant heel.  It happens more frequently at lower RPMs and it goes away completely at about 2000 RPM and above.  Our C-drive oil and transmission fluid look good.  A diver confirmed our propeller is clean, though he did ask me if the propeller pivots side to side when he came up.  I think he had noticed there is a bit of side to side play due to the rubber mount at the base of the C-drive housing connecting it to the keel.

 

Have any of you experienced something similar before?

 

Thanks,

 

Ryan and Kelly

SM 233 Iteration

Charleston, SC, USA