Grab the propeller and rock it from side to side. This is a test to see if the cutlass bearing is worn out. There should be minimal play between the cutlass bearing and the propeller shaft. When the bearing begins to break up this will cause strong vibrations in the stern. BoatWorks by editors of Sail Magazine covers this. This book is a series of published articles. There is a 6 page chapter on replacing the cutlass bearing, the chapter after that is Stuffing Box Maintenance. It's not that hard to do for the DIY person with this book as the instructions are good identifying what is happening in each picture, but does take time.
Last edited by LakeSuperiorGeezer; 02-28-2011 at 11:03 AM.