I have recently developed a knocking in the prop-shaft which is coming either from the
hull passage (let's say skeg) or the strut support bracket before the prop. This only happens
engine idling when the drive is not engaged or engaged at
engine speeds below 1000rpm (if I increase engine speed without engaging drive rattle ceases). If I shake the shaft from inside before the
shaft seal I can effect the knocking sound. I suspect the BTR Silverline cutlass bearing is going out and wondered if anyone has replaced one of these himself and how urgently I should address this (does bearing degradation accelerate quickly?)
JP
1978 nc33 Sean Seamour III