Just renewed the cutless bearing on my Merry Fisher 655 ( see my previous post ).
I suspect one of the main reasons why the bearing wore out prematurely is because the shaft is not aligned correctly. It appears that the engine will need to be lifted on the adjusters by about 1/4 to 1/2 an inch to ensure that the shaft is in the centre of the prop. shaft tube.
Hi. Had the same problem with our 4 yr old Jeanneau, the Gearbox coupling / Shaft coupling was found to be 30 thou out ! The mechanic said It had been like that from new as he had to move the engine over 2” at the front and re-drill the feet to get a fixing. I urge all boat owners with Shafts to get their Couplings checked when being serviced as our mechanic said he used to check new boats for a dealer because the dealer was concerned that the factories were chucking out boats without checking alignments. He found most boats well outside the acceptable tolerances.
Hi, I am currently looking at buying a boat that has had both shafts replaced (long story, not relevant). The boat yard did the installation when the boat was out of the water, and during the sea trial I get that it was not right.
The repair and more importantly the alignment of the shafts had been done when the boat was out of the water, and on getting a specialist to have a look at this it turns out that the alignment must be done when the boat is in the water, because it is only when the boat is in the water that it is in its natural shape.
So if you are checking the alignment during your winter service, this should be done only when the boat is in the water, as the boat is not in its normal shape when it's out of the water and this will throw the alignment off.