I get lots of comments to the effect that I make these jobs look too easy. They are easy. It does not mean they don't get frustrating though! I wanted to use this post to assure readers that I face the same obstacles as everyone when working on sail boats. This post is how boat jobs often go with one problem leading to or unmasking yet another. I call it the snowball effect.


This job was to be a simple shaft, cutlass, coupling & prop replacement but oh how things change when you get going. The boat, a mid eighties Ericson 34, has relatively low engine hours for her age but exhibited a very high level of vibration.


After I pressed out the cutlass bearing it became very apparent just how badly the vessel was misaligned.


Not only was the engine sitting far to low in the shaft log, and the shaft was thumping it when the engine was in gear, but it was also not passing through either the shaft log or the cutlass even close to parallel. The minute the cutlass came out the shaft sprang up and into the top of the strut. While boats can lose some alignment out of water it is usually in the order of thousandths of an inch when measured at the shaft coupling. My own CS looses about .001" from in water to out in terms of alignment and she has a longer shaft. This boat has a fairly short shaft and robust engine bed area so flex was clearly not causing this level of alignment issues. Read on and you'll find out the real reason this motor was so badly aligned.