Its Maureen not David. I'm captnautigal!!! We are a not your ordinary cruising couple. I've been captaining boats for about twenty years. Even have my Masters. My experience is extensive in the Bahamas, I ran a boat from Nova Scotia back to the states and crewed a bit in Alaska. Can't count the number of times up and down the ICW over the years. I do most of the minor maintanence myself. We always joke and tell people David is in charge of the mating on the boat, since he is not very mechanical, and they keep asking him questions!!!
With that said, following is an explanation regarding the half bearings from Gregg Burdick. When we started having the vibration/leaking seal issues, I knew Stuart Yacht was the place to go to get to the bottom of this. I have complete confidence in Gregg and his team. Their thorough knowledge all boats, including PDQ's is impressive. We wouldn't consider another yard!
With the full bearing at the propeller end of the shaft, and the support of
the gearbox coupling at the front end of the shaft, a half bearing is all
that is needed. A full bearing would be ok, but not necessary. This all
changes for other vessels/ shaft size, etc. The calculation is based on
shaft size and alloy, engine HP, and gear box ratio. A shaft should be
supported along its length as dictated by such a formula, although the
formula was not needed in this instance as there were not good options, and
the position of the half bearing just happens to be roughly at the halfway
point on the shaft.
The ID of the bearing is the same as the shaft (naturally). The OD of the
shell is less due to the tube dimension. Easier to use a lesser OD than to
machine the tube.
Gregg Burdick STUART YACHT 450 SW Salerno Road, Stuart, FL 34997 772