Hi, My buddy developed a vibration on his SR a couple weeks ago. He was cruising along at around 20 knots in deep water when this occurred. He did not hit anything and he assumed he must have picked up a submerged piece of line. A week later on a short haul he discovered his shaft was broken between the wheel hub and the cutlass bearing. Lucky enough he did not loose the wheel and made it home ok. He did not have any vibration prior to the break. So, my question is, could this be a result of fatigue or age? He said the shaft was 18 yrs old and maybe it had lived its life. I can't buy that and I wonder if there is another culprit. I have not seen the victim yet to see if there was an electrolysis issue but I doubt it. Can you give us something to look for ?